Czech Technical University In Prague Research Articles

How the COVID-19 changed the hands-on laboratory classes of electrical measurement

This article depicts how COVID-19 affected practical teaching at Czech Technical University in Prague, Faculty of Electrical Engineering, Department of Measurement. It introduces the subject of Electrical Measurement and its hands-on laboratory classes. The course applies to more than 100 undergraduate students per semester. Since COVID-19 mainly affected the teaching of the hands-on laboratory courses, the article narrates how the COVID-19 lockdown has changed classes. An experience with the rapid transformation of lectures during the lockdown focusing on the hands-on laboratory classes is discussed, and the improvements that have been done to preserve its objectives, but also to adapt them to another possible lockdown, and the need to switch to the distance teaching, is revealed. The changes have been inspired by the results of a survey carried out among more than 250 students. The outline of the laboratory tasks transformation with an emphasis on the possibility of switching the real face-to-face measurement to the distance teaching remote lectures is described. The change includes reducing the number of laboratory tasks taught while preserving most of the objectives. All 11 new laboratory tasks are described in detail, and it is discussed how the possible change from hands-on to remote classes will affect every task.

Proposal of point-wise power reconstruction for IRT-4M fuel assemblies in coupled Monte-Carlo calculations

Current efforts to develop high-fidelity multi-physics tools for research reactors with IRT-4M fuel leads to the involvement of Monte-Carlo transport and subchannel thermo-hydraulic codes in the process of safety assessment. Monte-Carlo based neutronic codes are often used as a reference tool and are suitable for a prediction of a detailed power distribution. This paper proposes a method of the point-wise power reconstruction based on a Radial Basis Function (RBF) interpolation for complicated irregular geometries and compares different detector functionalities of the Serpent2 code from the time efficiency point of view. Furthermore, a preliminary validation of the applied method for IRT-4M in a subchannel code SUBSALS mesh is presented. This code is currently under the  evelopment at the Research Centre Rež and the Czech Technical University in Prague and focuses on the thermohydraulic analysis of IRT type fuel assemblies.

Opportunities of experiential education in chemical technology and engineering

The University of Chemistry and Technology Prague, the Czech Technical University in Prague and ORLEN Unipetrol have established a common University center in the production facility of the refinery-petrochemical complex in Litvínov, Czech Republic. The university center offers higher education to more than 50 students in bachelor and master programs. The connection between the chemical industry and the academic environment has created a unique opportunity to apply experiential learning in many areas of teaching. The University center uses a newly built Training facility, which is equipped with several modules for training operators, engineers and, currently, students. Thanks to the attractiveness of the environment of the training facility premises, the target group of students has been extended to secondary and even primary schools. The University center organizes regular practice for secondary and primary schools at the training facility. The aim of these activities is to practice systematically modern methods of education through experience and to make technical disciplines as popular as possible among young students. Regionally, this experiential education system has achieved high popularity and, in addition to the University center own students, more than 500 students from around 30 secondary and primary schools go through the program every year.

Design Procedure for Stainless Steel Slender I Section Members in Bending

AbstractStainless steel welded I sections are used in structures not as often as cold‐rolled hollow sections or laser‐welded sections. But the design rules for both local buckling of very slender sections as well as lateral torsional buckling reduction factors are based on a very limited experimental and numerical research. For this reason, a new research covering these phenomena was carried out at the Czech Technical University in Prague. The contribution shows a numerical parametric study of welded slender stainless steel I‐section beams as a follow‐up of previous experimental program. The numerical study based on a validated FE model was carried out to develop a procedure for LTB of I section beams. The proposal follows the procedure of Taras, which is part of prEN 1993‐1‐1:2019, where modified constants are proposed. It was also found, that the local buckling reduction factor used in EN 1993‐1‐4:2006 may be unsafe for ordinary welded sections. The procedure in the Eurocode was developed mainly for SHS/RHS and laser‐welded sections. These fabrication methods result in significantly lower geometrical imperfections and slightly lower residual stresses than common welding methods (e.g. MIG). Therefore, a safe procedure proposal for Class 4 welded section resistance was also provided, despite not being the focus of the paper.

Experimental and Numerical Studies of Bolted Lap Joints at Elevated Temperature

AbstractThis paper presents an experimental and numerical studies of bolted double lap joints at ambient and elevated temperatures. Nine experiments conducted at the Czech Technical University in Prague investigated the mechanical behavior of bolted lap joints at 20°, 400° and 600°C. The design strengths of steel joints subjected to tensile forces are predicted using European standards for steel structures. The general finite element (FE) software ABAQUS/Standard 6.14 is employed for the numerical analysis. In this work, different numerical models are prepared to investigate a modeling technique of the bolted joints The plates are modelled using solid and shell elements and the bolt is represented by solid element and a combination of beam elements coupled to surfaces. All the studied models consider the contact behavior. The numerical models are validated using data from experimental tests. The analytical model serves for verification of numerical models. The validation and verification approved the numerical models. Consequently, the modeling techniques used in this research can give reasonable results to predict the resistance bolted joints at elevated temperature and can be used to predict the resistance in design level.

First-Year Engineering Students’ Strategies for Taking Exams

Student drop-out is one of the most critical issues that higher educational institutions face nowadays. The problem is significant for first-year students. These freshmen are especially at risk of failing due to the transition from different educational settings at high school. Thanks to the massive boom of Information and Communication Technologies, universities have started to collect a vast amount of study- and student-related data. Teachers can use the collected information to support students at risk of failing their studies. At the Faculty of Mechanical Engineering, Czech Technical University in Prague, the situation is no different, and first-year students are a vulnerable group similar to other institutions. The most critical part of the first year is the first exam period. One of the essential skills the student needs to develop is planning for exams. The presented research aims to explore the exam-taking patterns of first-year students. Data of 361 first-year students have been analysed and used to construct “layered” Markov chain probabilistic graphs. The graphs have revealed interesting behavioural patterns within the groups of successful and unsuccessful students.

Online teaching of practical classes under the Covid-19 restrictions

COVID -19 pandemic and its restrictions bring new challenges to all aspects and phases of higher education. At universities, new remote formats have been developed and deployed for lectures and laboratory exercises. This article addresses challenges and introduces the new experience with lectures and laboratory classes during the pandemic time at the Department of Measurement of the Czech Technical University in Prague, Faculty of Electrical Engineering. Based on the student survey of more than 250 students describes the possibilities of how to adapt the lectures during the lockdown. The article also introduces the Home Lab, a tool developed in the department that helps in distance teaching practical electronic classes. Home Lab includes two parts with functional groups, a Laboratory Experimental Device and a System of Measurement Instruments. The article also shows the opportunity for suitable remote exercises and variants of circuits that can be easily assembled and measured using Software Defined Instrument based on various microcontrollers. A detailed description of all Software Defined Instruments is also present. During the Pandemic, the home lab model was successfully practically verified during distance learning in three subjects, with more than 150 students per semester. It has also been shown that the Home Lab can be successfully deployed for a semester project. The article also presents experience with the teaching software-oriented courses. At the end of the article, practical knowledge and an experience from distance teaching during a three-semester lockdown are shared.

Digital Track Map for the VEXA expert system

This paper aims to summarize possible solutions of a Digital Track Map proposal, designed to become a data source for the VEXA decision-making system. The VEXA project is carried out in cooperation of the Department of Applied Mathematics at the Czech Technical University in Prague – Faculty of Transportation Sciences and the AŽD Praha s. r. o. company.The Digital Track Map is an indispensable data source describing the railway line intended for the VEXA supervised trains operation and its surroundings. Being created in the ArcGIS Pro software environment, the digital map allows individual objects to be visualized and handled as standard GIS features and described by related data stored in a geodatabase.Depending on the object class, the object location can be expressed in different ways. Not only physical location (directly expressible using GIS features) but also functional location (as the objects relate to a particular track) must be considered.

Accident rate of regional railway vehicles at railway crossings for the years 2014 to 2018

From a societal point of view, there are growing demands to increase traffic safety and reduce the risk of accidents of rail and road vehicles. The research to increase the safety of railway vehicles, which is carried out at the Faculty of Mechanical Engineering of the Czech Technical University in Prague, aims to increase the active and passive safety of railway vehicles. Components and systems of active safety are designed to reduce the risk of an accident. Components and systems of passive safety are designed to minimize the consequences of accidents. One of the parts of the active safety of railway vehicles is the condition and safety of the railway lines on which the railway vehicle is operated. The first part of the article focuses on the evaluation of accident statistics of railway vehicles with other road users at railway crossings for the years 2014 to 2018 with regard to the cause of the accident and the level of security of railway crossings. The conclusion of the article is devoted to proposals for solutions that could lead to a reduction in accidents at railway crossings.

Artificial Intelligence and Women Researchers in the Czech Republic

Artificial intelligence as a research area has been continuously growing for several decades. Many applications were developed in various domains. Medicine and health care have attracted more intensive attention thanks to rapid technological development that has accelerated generation of large volumes of data requiring intelligent analysis and evaluation. This article illustrates, through examples of women researchers and selected AI projects in medicine, the wide spectrum of applications developed during the last fifteen years in the Czech Republic, and in particular at the Czech Technical University in Prague. Women researchers played an important and irreplaceable role since the advent of AI research in the Czech Republic. By their example, they motivated many young female students to join the community and start their research career in the AI area. They frequently participated in research projects led by the senior women researchers. The presented overview of projects illustrates the diversity of the medical area and the potential of AI methods that can be used for solving data- and knowledge-intensive problems. We briefly touch on the AI study programs. In conclusion, we point out the future challenges in AI and its applications in medicine and health care.

Tests of Glass Insulating Panels with Embedded Laminated Point Connections

Embedded laminated point connections represent a progressive way of glass structures connecting. However, detail information about their performance is not available yet and the design procedure is mostly based on experimental work and previous experience of designers. Within an ongoing research at the Faculty of Civil Engineering of the Czech Technical University in Prague, a set of real-scale insulating glass panels with embedded laminated point connections was tested. The goal of the experiment was to determine the load bearing capacity and characteristics of this type of glass panel under short-term and long-term loads. There were three different types of panels used for the experiment. The specimens consisted of different combinations of glass plies (ESG, TVG) and plies of different thicknesses. However, all the specimens were identically sized and there was one embedded steel countersunk bolt liners in each panel’s corner. The laminated glass plies were bonded by two layers of an EVA foil in all cases. During the experiment, all the samples were placed horizontally using the embedded point connections. The applied load was gradually increasing until the collapse. Vertical deflections in specific points of the samples were measured. The temperature and the humidity were monitored as well.

Development of a 10 kW class axial impulse single stage turboexpander for a micro-CHP ORC unit

Development of micro ORC systems with 1-15 kW power output for micro-cogeneration and waste heat recovery at the Czech Technical University in Prague, University Centre for Energy Efficient Buildings (CTU UCEEB) has over ten years of history with many successes. These include 6 different ORC units, all with in-house designed rotary vane expanders (RVE) of many versions throughout this development. Among main advantages of the RVE belong relatively simple and robust design at low cost even at very small series of single-unit production and all that with acceptable efficiency. The ORC units operate with hexamethyldisiloxane (MM) working fluid at high pressure ratios and expansion ratios and the isentropic efficiency of RVE has a limit at these conditions around 60%, often however only at values around 50%. While this might be enough on a cost side for commercialization of this technology, in pursuit of higher efficiency solutions, different expander technology needs to be selected. A turbo-expander is a logical choice with prospect of higher efficiency. At the same time, a literature review has found a lack of reported detailed experimental data for micro (5-50 kW) turbo-expanders, possibly hindering global development towards economically feasible solutions. A project named Dexpand, “Optimised expanders for small-scale distributed energy systems” aims at these issues by objectives in designing, optimizing, manufacturing and testing several ORC expanders with MM and isobutane and their subsequent performance mapping and comparison. One major task is a design of a turboexpander for a 120 kWth biomass fired microcogeneration ORC unit currently operated at the CTU UCEEB. An axial impulse single stage turboexpander was selected as a suitable choice, providing a prospect of a decent efficiency at technically manageable rotational speed and size. This paper provides a detail of currently performed design activities, starting from boundary conditions specification, over development and optimization of a 1D model, preliminary 2D CFD calculations and finishing in a state of a robust and detailed 3D CFD model with a real gas model. Note that the working fluid, high molar mass organic vapour, is highly non-ideal in its behaviour and the flow conditions with pressure design ratio around 13 is highly supersonic (nozzle outlet isentropic Mach number exceeds 2). The current results based on 3D CFD indicate a prospect of an isentropic efficiency 71% at mechanical power output of 11 kW. Lastly, ongoing and future work is outlined, which includes aerodynamic optimization based on the developed 3D CFD model and construction design of the entire turbine assembly.

Application of the single-engine taxi-out procedure for commercial transport, focusing on the Airbus A320 fleet

There is currently a lot of pressure on airlines to reduce emissions, noise and fuel consumption. Another aspect is the drive to reduce operating costs, which leads to investment into the new technologies and also to the introduction of new procedures. One of these procedures is the so-called 'Single-engine Taxi-out', which aims to save fuel during taxiing. Together with this, the costs for the entire flight are reduced. Research at the department of Air Transport at the Faculty of Transportation Sciences of the Czech Technical University in Prague is underway to reduce the financial costs and emissions produced during each flight. One successful solution is to reduce emissions and the associated cost by using single-engine taxi procedures.

Modelling of multiphase solid-liquid laminar flow with non-Newtonian carrier in pipelines using a layered model

This paper discusses two-phase laminar flows of mixtures of solids in non-Newtonian carrier consisting of spherical particles in a 50-mm pipe at the Czech Technical University in Prague. Special attention is paid to the frictional head loss and thickness of transport layers. For the prediction of various transport characteristics, a layered model is used. Suitability of the layered model to predict the transport characteristics is investigated. Prediction results are compared to own experimental data.

About The Author

Abdullahi Kawu is interested in research in Human-Computer Interaction, Digital Health and ICT4D, hence most of his works are in those domains. He is passionate about people and technology, in particular exploring their engagements with technology. He is currently a Lecturer at Ibrahim Badamasi Babangida University, Lapai, Nigeria and a PhD research fellow with TU Dublin under the Science Foundation Ireland (SFI) Centre for Research Training in Digitally-Enhanced Reality (d-real) program. Earlier on, he obtained an MSc in Advanced Computer Science (Distinction) with interest in Human-Computer Interaction from Newcastle University, UK. He has also worked as a Consultant Staff to international development organisations like Malaria Consortium, World Bank and UNDP where he had the rare opportunity to learn and apply technical, leadership, project management, and Monitoring and Evaluation (M&E) skills in health projects.Email address: abdullahikawu@ibbu.edu.ng ORCID: 0000-0003-2531-9539Akinyinka Tosin Akindele is an instructional Designer and eTutor at LAUTECH Open and Distance Learning (LODLC), Nigeria. He also works as eLearning Consultant for Kampala International University, Uganda. He has over 8 years’ experience and is skilled in various eLearning technologies such as administration of LMS, curriculum and course authoring, creation and editing of multimedia (videos, animations and graphics) etc. He has trained diverse stakeholders on Blended Learning and actively participating in several eLearning projects locally and internationally including Partnership for Blended Learning (PEBL) West Africa sponsored by Association of Commonwealth Universities; Carbon Literacy for Youth Employability and Job Creation by British Council; Digital Innovation Skill Hub (DISH) by Dutch Ministry of Foreign Affairs Orange Knowledge Program etc. Mr Akindele holds an MSc degree in Computer Science from LAUTECH, Nigeria and he is presently pursuing his Ph.D. He has authored several articles on Distance Education and application of Artificial Intelligence to Health, Education and other related areas.Email address: akinyinka.akindele@kiu.ac.ug ORCID: 0000-0002-7027-466XAli Mtiraoui, a graduate of the Faculty of Medicine of Sousse (MD), the University of Montreal (MSc, community health) and the Pierre and Marie Curie University of Paris (statistics applied in epidemiology), is Director of the Laboratory of research “Quality of care and management of health services”, Former President of the University of Sousse, Honorary Dean and former Director of the Department of Family and Community Medicine of the Faculty of Medicine of Sousse. The quality of services and the management of services (education and health) are at the center of his professional concerns. He has worked at all levels of Tunisia's health care system and has carried out several consultation and expertise mandates in several fields, both nationally and internationally (development of intervention plans at the regard to health problems, design of curriculum & training programs, management of health services & mobilization of human resources, strategic planning, accreditation and certification, etc.).Email address: ali.mtiraoui@gmail.com ORCID: 0000-0002-6990-955XAliya Aktau received her MSc degree in Computer Science from Leiden University, The Netherlands, in 2020. She is now a PhD candidate at Leiden University Medical Center (LUMC) and teaching Data Collection, Wrangling, Analysis and Visualization at Suleyman University, Kazakhstan. Her research interests include FAIR Data Science and FAIR Data Management. She works as a data curator for medical health research.Email address: aleka.aktau@gmail.com; a.aktau@lumc.nl ORCID: 0000-0003-4942-2725Anthony Wachira graduated from the University of Nairobi with a BSc. Honors in Mathematics and Computer Science in 1988 and an MBA in Management Information Systems and Strategic Management for the same University in 2001. His MBA project was titled Ergonomic Factors Considered in Information Systems Implemented in Kenya: A Case of Firms in Nairobi. He is currently enrolled for PhD in Healthcare Management at the Institute of Healthcare Management of the Strathmore Business School — Strathmore University. He has been deeply involved in research on the provision of ICT solutions across many sectors and at various levels, the last two being ICT Services Director, Strathmore University and GM-ICT, Kenya Airports Authority. He chaired the inter-agency committee on border security in 2007, where one of the principal outcomes was the proposed single identification source for civil registration and vital statistics for all persons within the territory of Kenya using biometric data capture with the objective of creating Big Data.Email address: anto.wash@gmail.com ORCID: 0000-0002-0344-4403António Cartaxo (1987, Lisbon) visited in 2019 a research project on HIV prevention and care in Coastal Kenya, after which he became interested in access to healthcare. Since January 2020 he has been a PhD aspirant at Leiden University within the Globalisation Accessibility Innovation and Care network. His research focuses on participation in digital health innovation and health orientations in informal settlements in Nairobi, Kenya.Email address: am.cartaxo@gmail.com ORCID: 0000-0002-1276-1179Araya Abrha Medhanyie holds a PhD and is associate professor of public health at the School of Public Health at Mekelle University, Ethiopia. He has seventeen years of work experience in teaching, research, and community service. His research interests and professional career focus mainly in Global Health and Development. He is interested and has been building his research career in multidisciplinary and implementation research that integrates health systems, maternal and newborn health, health systems leadership and governance, health policy, digital Health and social transformation. Methodologically, he is interested and keen in specializing his capacity in implementation research, diffusion of innovations and scale-up of proven health interventions. He is passionate about serving humanity through research, education and leadership. He enjoys reading and writing about social change, leadership and development. He is Country Coordinator of VODAN-Africa.Email address: araya.medhanyie@gmail.com ORCID: 0000-0002-9328-684XAwotunde Joseph Bamidele received his B.Tech. degree in Mathematics/Computer Science from Federal University of Technology, Minna, Nigeria, in 2007. M.Sc. and Ph.D. degrees in Computer Science from the University of Ilorin, Ilorin, Nigeria, in 2014 and 2019 respectively. Since 2019, he has been a Lecturer with the Department of Computer Science, University, of Ilorin, Ilorin, Nigeria. He is the author of more than 40 articles, 30 chapter in book, and more than 25 Conference Proceedings in reputable outlets like Elsevier, Springer Taylor and Francis among others. His research interests include Information Security, Cybersecurity, Bioinformatics Artificial Intelligence, Internet of Medical Things, Wireless Body Sensor Networks, Wireless Networks, Telemedicine, Medical Imaging, Software Engineering, and Biometrics. He is a member of International Association of Engineers and Computer Scientist (MIAENG), Computer Professional Registration Council of Nigeria (MCPN), Nigeria Computer Society (MNCS), and Internet Society.Email address: awotunde.jb@unilorin.edu.ng ORCID: 0000-0002-1020-4432Balyejusa Gusite is a staff member in the directorate of research, innovation, consultancy and extension of Kampala international university serving as a data communications officer. He is also a data steward (Expert) in virus outbreak data network (VODAN-A). Gusite is currently pursuing a masters of science in information systems (Msc.IS) at Kampala International University, He holds a first class Bsc. Information technology from KIU. As an information technology personnel, Gusite is a freelancer developer, with bias in automation systems, data science, deep learning, Machine learning, computer vision and security systems.Email address: gusite.balyejusa@kiu.ac.ug ORCID: 0000-0003-4515-6052Bert Meerman is the Director of the GO FAIR FOUNDATION (GFF), based in Leiden, the Netherlands. Involved in different EOSC Projects (EOSC Secretariat and EOSC Nordic). GFF focus is on the promotion, protection and the correct implementation of the FAIR Principles, next to the transfer of knowledge on the application of FAIR.Email address: b.meerman@gofairfoundation.org ORCID: 0000-0002-0071-2660Dwy Bagus earned his Master degree in Electrical Engineering and Informatics from Institut Teknologi Bandung (ITB), Indonesia, in 2018. He is now a lecturer and software architect in Politeknik Statistika STIS, Indonesia. His research interests include software engineerings such as cloud computing, blockchain, and artificial intelligence.Erik Flikkenschild was educated in the early days of computer science as an electronic engineer (innovative curriculum by TU Delft, Antony Fokker school and MTS The Hague (1974). He is now an information manager and IT architect (LUMC) and Deputy Director (Go-FAIR foundation). His computer science interest is the design of the Internet of FAIR Data Services with a focus on data protection, starting with policy (risk assessment) translating in the IT design of access control measures.Email address: e.flikkenschild@lumc.nl Alternative email: erikf@gofair.foundation ORCID: 0000-0002-7285-1651Ezekiel Ogundepo In the fields of mathematics and statistics, Ezekiel is a knowledgeable and creative professional. He holds a master's degree from the African Institute for Mathematical Sciences (AIMS), Rwanda, where he received a scholarship from MasterCard, and a first-class degree in statistics from the University of Ilorin, Nigeria. He has experience with the Rwanda Revenue Authority (RRA) and is a leading expert in advanced statistical modelling. He worked on the RRA team that developed the interactive taxpayer data portal and automated key statistical reports needed by internal and external users. Ezekiel is currently employed by 54gene (a biotechnology company) as a Data Specialist and has made contributions to the ralger web scraping R package and the Big Book of R. He is a certified instructor for Rstudio Tidyverse, a data steward at Virus Outbreak Data Network (VODAN) Africa and Asia, and an active member of the Africa R programming community.Email address: ezekiel@datasciencenigeria.ai; ogundepoezekiel@gmail.comEzra Mwesigwa Highly enthusiastic about Health Informatics and ICT for development (ICT4D). Ezra has proficiency in Information Systems Analysis, Design and Development with over 6 years’ experience delivering electronic knowledge management solutions currently working as a DevOps Engineer at Makerere University Kampala (MAK) and Kampala International University (KIU). With a Msc. and Bsc in Information Systems, Ezra has been part of local and international project establishments in and outside Uganda serving within various technical capacities. Currently part of a wider multinational VODAN-Africa team developing and piloting a FAIR data architecture in 88 facilities across 7 countries in Africa, DevOps Consultant towards responsible anti-microbial use in refugee settlements within Uganda; a project funded by Pfizer, ICT consultant working through Makerere University Climate Change and Research Initiative-MUCCRI to develop a national climate change Knowledge Management System funded by Food and Agriculture Organization among many other notable involvements.Email address: mezra@cit.ac.ug ORCID: 0000-0003-2125-1012Esther Thea Inau is a PhD student studying in the Medical Informatics Department at the Universitätsmedizin (University of Medicine) Greifswald, Germany. Her PhD studies are based on implementing and evaluating the FAIRness of data obtained from health cohort studies in Germany.Email address: inaue@uni-greifswald.de ORCID: 0000-0002-8950-2239Francisca Oladipo, is a Professor of Computer Science and pioneer Director, Quality Assurance, Federal University Lokoja (FUL), Nigeria. She is a Consultant at the Tilburg School of Humanities and Digital Sciences of Tilburg University, Netherlands, and had served previously at Kampala International University (KIU), Uganda as the Director of Research, Innovations, and International relations. She has recently been appointed the Vice-Chancellor and Chief Executive Officer of Thomas Adewumi University, Nigeria.Email address: francisca.oladipo@kiu.ac.ug ORCID: 0000-0003-0584-9145Francis Kinyua Gathua facilitates development and implementation of appropriate youth and women livelihoods strategies; self and wage employment for self sustenance and resilience in Nairobi slums. With over 10 years in non-profit sector, Francis has solid, documented experience in project cycle management, behavioural/cognitive skills development, high maturity and knowledge of working with young people, team building, strategic planning, mentorship, collaboration, monitoring and evaluation. Francis is a certified life skills facilitator/trainer and manages Kamukunji Community Empowerment Initiative's (KCEI) vulnerable youth and women enablement project. Francis Holds a B.A and MA in Sociology from University of Nairobi.Email address: kgathua@gmail.comFredrick Obwanda is a healthcare management expert from Kenya, who worked at the Ministry of Health leading institutional, and policy agenda at the National Blood Transfusion Services, in addition to being a Sub-County Hospital Manager and Linked to Tangaza University at present.Email address: fobwanda@gmail.com ORCID: 0000-0002-8275-0926Gertjan van Stam has been involved with ICT in Africa since 1987. He holds a PhD in Culture Studies from Tilburg University, an MTech in ICT from Nelson Mandela University, and an engineering degree in telecommunications. His activities focus on mechanisms at the intersection of society and technology.Email address: gertjan@vanstam.net ORCID: 0000-0003-4618-6106Getu Tadele Taye is a lecturer in the department of Health Informatics at the college of health sciences Mekelle University (MU), Ethiopia. He has worked as a software engineer for almost 3 years prior to joining MU. He is an active member of digital health research and development center at MU. Currently, he is also working as country technical lead in the project Virus Outbreak Data Network Africa and Asia (VODANA). VODANA is a Global Open Findable, Accessible, Interoperable, and Reusable (GO FAIR) Implementation Network set up to help fight the COVID-19. He has vast research experience in Medical and IT Convergence technology and participated in national and international conferences and published journal papers on prestigious peer-review journals. He is interested in the concepts and technologies in data science, data FAIRification, eHealth Architecture (eHA) and making HISs interoperable. He holds a master's degree in Medical IT Convergence Engineering from Kumoh National Institute of Technology, South Korea.Email address: getu.tadele@gmail.com; getu.tadle@mu.edu.et ORCID: 0000-0002-9965-1801Hauwa Limanko Ibrahim is a research assistant with the New and Emerging Technology Research Group (NETReg), IBB University Lapai, Nigeria. She is interested in the design and evaluation of novel interactive technologies in low resource communities.Email address: ibrahimhauwa977@gmail.com ORCID: 0000000240566442Ibrahim Abdulahi is Head of the Department of Computer Science, Ibrahim Badamasi Babangida University, Lapai. He is Director ICT and Chairman New and Emerging Technologies Research group (NETREG). Ibrahim holds a PhD in Computing, a Senior Member of the IEEE. His research interest include: Future Internet (Information-Centric Networking), Operating Systems, Algorithms, AI, Bigdata, and Digital-Health. A Lecturer of Computing and the Director of Information and Communication Technology at IBB University, Lapai. Nigeria. He is a facilitator, editor and content writer of several Learning Management System (LMS) solutions.Email address: ibrojay01@gmail.com; ibrojay01@ibbu.edu.ng ORCID: 0000-0002-3467-1203Jamilu Yahaya Maipan-uku (Mr.) received his B.Sc. in Computer Science from Ibrahim Badamasi Babangida University Lapai (IBBUL, 2010), Niger State, Nigeria. Also, holds M.Sc. in Computer Networks from Universiti Putra Malaysia (UPM, 2016), Malaysia and Ph.D. (in view) in Computer Information Systems at Near East University, Cyprus with about 15 technical and international conference papers across SCOPUS, DBLP databases. His research interest includes; Grid Computing, Cloud Computing, Cyber Security, Artificial Intelligence, Machine Learning, and Deep Learning. He is a member of Nigeria Computer Society (NCS) and Internet Society of Nigeria (ISOC).Email address: jymaipanuku@ibbu.edu.ng ORCID: 0000-0001-8071-7295Mr. Joseph Elijah (M.Eng.) is a lecturer in the Department of Computer Science, Ibrahim Badamasi Babangida University, Lapai, Nigeria. He is a member of the council for the registration of Engineers in Nigeria, a member of the association for computing machinery, and the international association of Engineers (IAENG). His current research interests include intelligent systems, cognitive radio, microstrip antenna, and digital health.Email address: ibrojay01@gmail.com ORCID: 0000-0002-9922-9029Dr Katy Wolstencroft is an Assistant Professor in Bioinformatics at Leiden University. She has a Bachelor in Biochemistry (University of Leeds) and a Master and PhD in Bioinformatics (University of Manchester. Her research focuses on data and knowledge integration in the life sciences. She is an author of the FAIR guiding principles and is instrumental in the development of several FAIR data initiatives in systems biology, bioimaging and biomedicine, in addition to her activities in VODAN.Email address: k.j.wolstencroft@liacs.leidenuniv.nl ORCID: 0000-0002-1279-5133Klara Smits works at Tilburg University as a PhD candidate on the topic of human trafficking of Eritrean refugees in the digital era. Smits is interested in forced movement, and particularly the aspects of digitalisation, in the nexus of environmental, political and social problems. She has a MSc. in Forest and Nature Conservation with a specialisation in Sustainable Development Diplomacy.Email address: klarasmits@gmail.com ORCID: 0000-0003-1713-7057Kudakwashe Chindoza received his MCom Information Systems degree in 2015 (GZU), a BSc in Information Systems in 2006 (MSU) and a Post-Graduate Diploma in Higher and Tertiary Education in 2019 (GZU), Zimbabwe. He is a technical expert of VODAN-Africa in Zimbabwe. He is a PhD student with Tilburg University.Email address: chindozak@gmail.com; kchindoza@gzu.ac.zw (Official email) ORCID: 0000-0002-8346-5211Kibrom Fekadu Berhe is a Lecturer and researcher of Public policy and Development at Mekelle University, Ethiopia. He obtained MA degree in Public Policy and Sustainable Development from University of Gondar, Ethiopia in 2013 and Masters of Environmental Management from Massey University, New Zealand in 2015. He has over 10 years of experience in teaching research and community services in higher education institutions. He is currently working in consultancy, mediation, advocacy and research in Belgium.Email address: kiblid@gmail.com ORCID: 0000-0003-1728-5076Marek Suchánek is PhD student at Czech Technical University in Prague and University of Antwerp (double-degree programme). His research topic is about connecting conceptual modelling and software implementations beyond model-driven development. He obtained both master's and bachelor's degrees at CTU in Prague in Information Systems and Management. He actively participates on various projects such as Data Stewardship Wizard or FAIR Data Point.Email address: marek.suchanek@ds-wizard.org ORCID: 0000-0001-7525-9218Mariam Basajja is currently pursuing a PhD in Computer Science at Leiden University in the Netherlands. She obtained a master's degree in Advanced Computing, machine Learning and Data mining from the University of Bristol, UK and also has a master of Science in Computational Intelligence from University of Nairobi, Kenya. She also holds a bachelors in Applied Computer Technology with a concentration in Software Engineering from United States International University Africa. Her main areas of interest are around FAIR data, big data, databases, data analytics, cloud computing, ICT Infrastructure and others.Email address: mariam.basajja@gmail.com ORCID: 0000-0001-7710-8843Mariem Ghardallou received her Medical doctor degree from the Faculty of Medicine of Sousse, Tunisia, in 2011. She is now an Associate Professor in Community and Preventive Medicine at the Faculty of Medicine of Sousse, University of Sousse, Tunisia. She is currently the vice-dean of research and valorization of expertise at the Faculty of Medicine of Sousse and the country coordinator for Tunisia of VODAN Africa.Email address: ghardallou.m@gmail.com Alternative Adress: Mariem.Ghardallou@famso.u-sousse.tn ORCID: 0000-0001-9289-722XDr. Mia Stokmans is an associate professor at Tilburg University, Tilburg School of Humanities and Digital Sciences. Between 2008 and 2010 she was involved in the EUCIM-TE Comenius project co-funded by the European Commission, DG Education and Culture within the Lifelong Learning Programme to improve the pre- and in-service training of all teachers for their work with immigrant pupils by elaborating a competence-based European Core. Between 2011 and 2012 she participated in the ARKA-project about the valorisation of human capital of migrants in the European Union. She has participated in the NWO project Cost Benefit Analysis of Social Protection on Social Economic Resilience, the NWO project Mixed Migration Ethiopia, and the ZonMW project about care processes for dementia. Her main fields of interest are the role of attitudes and emotions in human decision making, social processes for behavioral change and mixed method approaches in doing research.Email address: M.J.W.Stokmans@tilburguniversity.edu ORCID: 0000-0002-7593-9632Mirjam van Reisen is Professor International Relations, Innovation and Care at Tilburg University and Professor of FAIR Data Science at the Leiden University Medical Centre (LUMC) at Leiden University. Van Reisen is Research Leader of the Globalization, Accessibility, Innovation and Care (GAIC) network. Her teaching experience includes, among others, the University of Pavia, Tilburg University, Amsterdam University College, Leiden University and the College of Europe. Van Reisen is the Director of the organisation Research Advisors & Experts Europe (RAEE) in Brussels. Van Reisen is the Coordinator of the Virus Outbreak Data Network (VODAN) Africa implementation network. Van Reisen was a member of the Dutch Advisory Council on International Affairs (AIV) and Chair of the Development Assistance Committee (COS) from 2013 to 2020. Van Reisen received the Golden Image Award in 2012 by President Ellen Johnson Sirleaf.Email address: mirjamvanreisen@gmail.com ORCID: 0000-0003-0627-8014Misha Stocker is a consultant with Research Assistants and Experts Europe in Brussels. He studied European governance with a double major from the University of Konstanz, Germany, and the University of Utrecht, The Netherlands. He received his bachelor degree in Liberal Arts and Sciences with a major in political science from the University College Roosevelt from Utrecht University. He carried out his internship in the Go FAIR foundation and his thesis investigated the EU policy making on FAIR Data.Email address: mishastocker@gmail.com ORCID: 0000-0003-0347-9953Morgane Wirtz is a PhD student at Tilburg University, a freelance journalist and a researcher for EEPA. She focuses on human right abuses, security in Sahel, migration and human trafficking on the Central Mediterranean Road. Based in Tunisia, she works for Le Point Afrique, Inkyfada and Hans Lucas. She is also a documentary filmmaker.Email address: morgane.wz@gmail.com ORCID: 0000-0002-2514-5797Mouhamed Mpezamihigo born in Uganda, is Vice Chancellor of Kampala International University and leader of the programme of the Digital Innovation and Skills Hub (DISH), and Chair of the Virus Outbreak Data Network - Africa, VODAN-Africa. He is board member of the African Institute for Capacity Development (AICAD), and Executive Committee member of the Interuniversity Council for East Africa (IUCEA) among many other obligations he holds.Email address: vc@kiu.ac.ug ORCID: 0000-0002-9700-3034Munyaradzi Mawere is a double professor, being a Full Professor of African Studies at Great Zimbabwe University (GZU), Zimbabwe and a Professor Extraordinarius of Interdisciplinary Research at the University of South Africa (UNISA), South Africa. Mawere has 310 publications to his credit, including 91 books, and over 200 book chapters and peer-reviewed journal articles published with internationally acclaimed publishers.Email address: munyaradzimawerem@gmail.com ORCID: 0000-0002-3684-6089Nambobi Mutwalibi is a Vodan Expert of the Virus Outbreak Data Network (VODAN) Africa implementation network. He is also a research assistant at Motion Analysis Research Lab, Islamic University in Uganda. He was a research assistant in the Technical and Vocational Education (TVE) department at Islamic University of Technology, Bangladesh (IUT, 2018). He holds a BSc. Technical Education (Islamic University of Technology, Dhaka, Bangladesh) specializing in computer science and engineering. His research interest on Disruptive Innovations, FAIR Data, JTBD, Wargaming Strategy, Game theory, Coopetition, Blue Ocean Strategy, Blended learning, Green Skills, TVET and ICTs in developing countries. He can be reached via his website: www.nambobi.com, email: hello@nambobi.com and contact +256701044034 Email address: nambobi.mutwalibi@kiu.ac.ug ORCID: 0000-0001-6822-616XObinna Osigwe is a Digital Media Professional at Kampala International University, Uganda and the Communications Lead at Virus Outbreak Data Network Africa (VODAN-Africa). His experience and competence spans across Computer Networking, Digital Marketing, Data Analysis, Online Reputation Management, Performance Measurement and has Consulted for several organizations in Nigeria and Uganda. Obinna has a Bachelor of Science in Computer Science from Nnamdi Azikiwe University Nigeria, and is currently a Master's Student in Project Management.Email address: obinna.osigwe@kiu.ac.ug ORCID: 0000-0001-7825-3591Oluwole Olumuyiwa Afolabi has more than a decade of experience working in an international organisation and has over time built his proficiency in PHP, MySQL, JavaScript, Ajax and several other programming languages. He has proficient skills with CSS, Self-Developed Content Management System (CMS), Microsoft Office Packages, CorelDraw, and a very good understanding of design and the use of the Adobe Creative Suite. He has obtained professional certifications including; PHP OOP: Object-Oriented Programming for Beginners - Certificate of Completion from UDEMY – 2018, Online Cambridge Certified Web Publisher from Cambridge Intercontinental University-2010, and a Diploma in Advanced Web Development from ECAND Nig. Ltd-2009. He is currently working with Kampala international University as a Web Administrator.Email address: oluwole.afolabi@kiu.ac.ug ORCID: 0000-0002-4007-6363Putu Hadi received his M.Sc degree in ICT in Business and the Public Sector from Leiden University, the Netherlands, in 2021. He is a PhD student with the Leiden University Medical Center (LUMC). He is now an ICT expert in Central Bureau of Statistics, Indonesia. His research interests include data governance and principles such as FAIR and open data. He is a technical team lead in VODAN-Africa on implementation in health facilities.Email address: putu.hadi.purnama.jati@umail.leidenuniv.nl ORCID: 0000-0002-6533-3709Reginald Nalugala is a postgraduate tutor at Tangaza University, specializing in social transformation. He trains research students in the PhD and Masters programme to draw on the SDGs to foster social transformation. At VODAN Africa and Asia, he is the country lead for Kenya where he coordinates the VODAN activities in Kenya. SDG 3 highlights the importance of health and wellbeing. This situation has been made worse by the COVID-19 pandemic. Reginald and the team are studying different methodologies on how to improve livelihoods of households affected by COVID-19 pandemic.Email address: reg.nanales@gmail.com ORCID: 0000-0002-3737-9777Ruduan Plug is an associated researcher with the Leiden University Medical Center and a scientist in machine learning and artificial intelligence at monitoring & control services of TNO. Previously he has been named a Google Scholar for his work on OpenAI's scalable meta-learning algorithm and he has worked with CEDAR at the Stanford Center for Biomedical Informatics Research. In addition, he has acted as a technical coordinator for VODAN, is active within the interdisciplinary GAIC research group of Tilburg University and is an ambassador for FAIR data and the European Open Science Cloud (EOSC) at the GO FAIR foundation. His research primarily focuses on the application and adaptation of machine learning, artificial intelligence and the architecture of interoperable, federated and distributed computational ecosystems for data-driven applications.Email address: ruudplug@gmail.com ORCID: 0000-0001-5146-6116Samson Yohannes Amare is a lecture in the department of Software Engineering, Mekelle University (MU). He is an active member of digital health research and development center at MU doing research, teaching and software development. Samson has been involved in most of the digital health activities done in MU. He has also been working on a couple of software development projects and implementation researches. He is actively working on the project Virus Outbreak Data Network Africa and Asia (VODANA), which is a Global Open Findable, Accessible, Interoperable, and Reusable (GO FAIR) Implementation Network set up to help fight COVID-19. He has also experience on software architecture and enterprise architecture development working closely with OpenHIE and the ministry of health. He has contributed during digital health blueprint development by the ministry of health. His research interests include digital health and data science. He holds a master's degree in Informatics Engineering from University of Algarve, Portugal.Email address: samsonya@gmail.com; samson.yohannes@mu.edu.et (Official email)Sara Nodehi received her MSc degree in ICT in Business and the Public Sector from Leiden University, the Netherlands, in 2021. Immediately after graduation, she started her work as a Ph.D. candidate at the Open University, the Netherlands. Her research interests include IT governance, Business/IT alignment, Information security management, and digital transformation.Email address: sara.nodehi95@gmail.com (preferred); s.nodehi@umail. leidenuniv.nl (work address) ORCID: 0000-0002-2919-1336Sakinat Folorunso is a computer science lecturer and researcher at Olabisi Onabanjo University, Ago Iwoye, Ogun State, Nigeria. She had a B. Tech in Computer Science from the Federal University of Technology, Akure, Ondo State, Nigeria. She also had an M. Sc and PhD in Computer science for the University of Ibadan, Ibadan, Oyo State, Nigeria. She has authored many journals and conference articles in Data mining, Machine Learning and Data Science.Email address: sakinat.folorunso@oouagoiwoye.edu.ng ORCID: 0000-0002-7058-8618Tesfit Gebremeskel Gebreslassie is a lecturer of Health Informatics at the school of public health, Mekelle University (MU). He has eight years of experience in electronic Health Management Information Systems as a program implementer and consultant to the Ministry of Health in the area of eHealth and health informatics initiatives. He has been engaged in the development and implementation of different health-related electronic health system. He has been working in the areas of eHealth Architecture and interoperability in collaboration with OpenHIE. He spends most of his time in reading and practising health information and innovation related trending ideas and developments. Tesfit is head of the digital health research and development center at Mekelle University. He holds a master's degree in Biostatistics and Health Informatics.Email address: tesfitgebremeskel@gmail.com ORCID: 0000-0001-9389-5584Tigist Abtamu is an Information Science expert with a multi-disciplinary orientation and qualifications. She worked in the field of information science for more than 10 years in the Ethiopian Public Health Institute. Currently she is working as e-health coordinator at Addis Ababa University, School of Public Health, Capacity Building and Mentorship Program to support the Ministry of health initiative in the area of Health Information System development in the country by strengthening the Health information system aiming to build local capacity to transform health data quality and information use for evidence-based decision making.Email address: tigist.habtamu@aau.edu.et; tigist12@yahoo.com ORCID: 0000-0001-6082-1060William Muhadi Nandwa holds a BSc. Microbiology and Biotechnology and an MSc. Epidemiology. He has worked at Pumwani Maternity Hospital in Kenya as a data steward under USAID Afya Jijini. Currently, he is the lead data steward and Country Coordinator for the VODAN-Kenya team. He also brings together the forum of all Country Coordinators of VODAN-Africa. He has undertaken further training in data management technology under the Phillips Foundation. His research experiences has been fundamental in the development of this paper.Email address: wmnandwa77@gmail.com ORCID: 0000-0002-2994-4916Wondimu Ayele is Assistant Professor Biostatistics and Health Informatics at School of Public Health, Addis Ababa University. Assistant Professor and Director Health Information Capacity Building and Mentorship Project (Preventive medicine). He is a coordinator in the Virus Outbreak data Network - Africa. He studied at the Institute of Medicine, Epidemiology, Health Informatics and Biometer, Martin Luther University, Halle (Saale), Germany. Data manager for Ebola Response (Diseases Surveillance).Email address: wondimu.ayele@aau.edu.et; wondaay@gmail.com ORCID: 0000-0001-5899-347XWhitney Atieno Otieno is an Highway Engineering student at Kenya Institute of Highways and Building Technology. She is a community worker at Majengo, Pumwani, in Nairobi, Kenya and a leader in the Kamukunji Community Empowerment Initiative (KCEI). She developed an interest with community work for she grew up in slums. She is a women's rights activist. In 2018, she joined Kenya Women in Justice Centres group. She is a community leader and associated with the Tangaza University College initiative with the community organization KACPEN on social transformation.Email address: atienowhitney6@gmail.comYan Liang has received a double BA from University of Minnesota Morris in Economics and Statistics and a MSc in Computer Science from Leiden University. Her interests are in cloud computing and big data management and she has contributed to the core architecture of VODAN. Yan is currently active as a data engineer at KPMG in Digital Assurance & Innovation and is a chair at the KPMG Dani Young Board.Email address: y.liang.2@umail.leidenuniv.nl; liangyan12138@gmail.com ORCID: 0000-0002-3860-725XYi Lin received his M.Sc degree in ICT in Business and Public Sectior from Leiden University, Netherlands, in 2021. He is now a research assistant at Leiden Institute of Advanced Computer Science (LIACS), Leiden University. His research interests focus on data analysis for business insight.Email address: y.lin@liacs.leidenuniv.nl ORCID: 0000-0002-9833-3457Zohra Touati received her Professional Master's Degree in Information and Communication Technology in 2008. She is now a Professor in Computer Science at the Faculty of Medicine of Sousse, University of Sousse, Tunisia.Email address: zohra.touati@live.fr ORCID: 0000-0002-8329-706X

The project of VR-2 subcritical assembly

The paper describes the project of VR-2 Subcritical assembly (SCA) which is being developed and built at the Czech Technical University in Prague (CTU). VR-2 SCA is to be placed in a building of already established facility of VR-1 Training reactor which has been successfully operated by CTU since 1990.CTU has decided to build the new nuclear facility (VR-2 SCA) even though it already operates one (VR-1 Training reactor). The main motivation is a worldwide large demand for education and training at nuclear research facilities. Currently, VR-1 Training reactor is reaching its maximum capacity, especially during a semester when the utilization reaches almost 100%. It is expected VR-2 SCA provides additional capacity for training and education in a field of nuclear engineering and enhances research possibilities at CTU. Interesting areas of research that could be addressed at the VR-2 reactor are: benchmark experiments, criticality safety studies, studies of accelerator driven systems and development/testing of radiation detection systems.VR-2 SCA is designed as an open pool vessel including a water-moderated uranium core. The core will consist of a combination of an enriched and natural uranium fuel. The SCA will be driven by a D-D neutron generator. The generator can operate in both continuous and pulse mode, and thus allowing pulse neutron source experiments. The facility keeps a high level of flexibility where many parameters can be changed, e.g. geometry of a core lattice, moderator temperature, water level etc.

Simple Laminated Glass Panels with Embedded Point Connection under Short-Term Load

Glass is a very attractive material for contemporary architecture. The trend is to achieve a maximum transparency of structures; therefore it becomes common to use glass as a material for load-bearing structural elements. Glass facades, roofs, beams or columns are widely used in buildings. The problematic part of a glass structure design is the connection between the glass pieces or between the glass elements and substructures from another material (e.g. steel, concrete etc.). The connection must be capable of bearing the stresses performing during the lifetime period and it should be as unobtrusive as possible at the same time. The ongoing research at the Faculty of Civil Engineering of the Czech Technical University in Prague is focused on an embedded laminated point connection for glass structures. Within this research, the real-scale glass panels were tested. The samples consisted of two glass plies bonded with the EVA foil. For the undrilled ply, the float glass was used in all cases. The thermally toughened or the heat strengthened glass was used for the pre-drilled ply. There was one embedded steel countersunk bolt with HDPE liners placed in each corner of the sample. During the experiment, the samples were horizontally placed using the embedded bolts. The load-bearing capacity of the six tested specimens was determined. The load was applied in several loading and unloading cycles until the collapse of the first embedded connection. If the glass panel failed before the connection, the sample was completely unloaded and then the load was gradually increasing until the collapse of the connection. Vertical deflection and the stresses at two different points were measured during the loading cycles. The humidity and the temperature were also monitored. The experiment showed the way of collapse and a short-term load-bearing capacity of a laminated glass panel with four embedded point connections.

Effect of Energy Dissipation on Scour Hole Development Downstream of the Chute

An energy dissipation on hydraulic structures is a scientifically highly examined field of study. Gained knowledge can be used to ensure the safety of the hydraulic structures and the channels which is crucial during floods. Above that, those structures are also part of the critical infrastructure therefore their function is necessary. It is assumed that in the Czech Republic the precipitation distribution is changing due to climate change thus episodes of extreme floods may be observed more often. The paper brings brand new knowledge on the kinetic energy dissipation on the chute and in the stilling basin and its impact on the riverbed scour hole development. The presented research was conducted in the Water Management Experimental Centre of Czech Technical University in Prague, Faculty of Civil Engineering. The research aimed to examine the energy dissipation mechanism on different geometric modifications of the construction of spillway chute and stilling basin and its impact on the process of scour hole development. These various types of dams’ flood safety equipment were examined in the hydraulic laboratory: an elementary form of the spillway without any stilling basin; the elementary form of the spillway and the stilling basin (crest and spillway channel had the same width); the chute width was reduced, and the stilling basin had the full width; steps were added on the narrowed chute and the and stilling basin had the full width; only the spillway crest was reduced to a half-width; only the stilling basin width was smoothly reduced; the chute’s width was smoothly reduced along the chute and the stilling basin had full width; the chute’s width was smoothly reduced along the chute and the stilling basin had the width reduced to a half. The flow, water levels, scour hole and deposit dimensions were measured. Then the amount of energy dissipated was computed. The correlation and connection between energy dissipation and scour hole development was investigated. These outcomes can be used as a recommendation of an appropriate construction design to provide better flood safety of the hydraulic structure.

Advanced Design of Steel to Timber Bolted Joints

AbstractThe paper is focused on the topic of steel to timber joints with inserted steel sheet. These joints have significantly higher load‐bearing capacity compared to the classic timber joints with timber parts only. In order to study the mechanical behaviour of these joints with inserted steel sheet in tension, experiments were prepared at Czech Technical University in Prague, and the numerical model was created using the ABAQUS code. The test specimens were designed for the most accurate approximation of realistically designed structures based on the recommendation given in the standard. The eight different specimens varied in the diameter of the fastener, the size of the steel washers, the number of rows of fasteners, their spacing and the strength class of the timber. For this experimental study, a set of timber of the C24 strength class and glue‐laminated timber of GL24h strength class was prepared. Results of experimental work cover failure modes of timber and diagrams of displacement in control points. In the model, timber was described as an orthotropic elastic material with defined nine independent elastic constants. Contact bonds were defined between the bolts and the timber member as well as between the bolts and the steel based on experiments. Part of the work is dedicated to the verification and validation of the numerical model. The verification of the numerical model was based on the results of the analytical model given in the current design standard. The validation approved the good agreement of the numerical model with results of tension tests, with maximal deviation up to 19 %.

Parametric study of stainless steel slender I‐section beams

AbstractThe contribution shows a numerical parametric study and experimental research of welded slender stainless steel I‐section beams. Difference in behavior of stainless steel and common carbon steel members is generally known, but design of stainless steel members has been established mainly for hollow sections (CHS, SHS/RHS) as these are the typical stainless steel profiles. Currently, open stainless steel sections are also being used in structures and the design rules for both local buckling of very slender sections as well as lateral torsional buckling reduction factors are based on very limited experimental and numerical research. For this reason new research covering these phenomena was carried out at the Czech Technical University in Prague. A numerical model was used for design of test arrangement, the geometrically and materially nonlinear analysis with imperfection was made in software Abaqus. The experimental program consisted of six stainless steel beam tests being used for a model validation. The tests employed two stainless steel materials (austenitic and ferritic steel), one section slenderness (Class 4 for web and flange) and three beam slenderness. A parametric study based on the validated numerical model was carried out with the main focus on lateral‐torsional buckling of slender Class 3 and Class 4 welded I‐sections. A comparison to the existing design procedures is shown. In limited amount, resistance of Class 4 stainless steel sections in bending was also investigated.