Structural System Research Articles

The Relationship between Building Information Modeling (BIM) and Precast Concrete Structures

Due to the fact that a major part of the financial resources of each country is spent in the construction industry of that country, the effectiveness of governments from this industry, especially in developing countries, is very high. In recent years, it has been noticed in the world. Among the advantages of using the prefabricated industry, we can mention the production of parts in a short period of time, low cost and high quality. Currently, many projects undergo such changes that it is necessary to reduce the negative effects imposed on projects by using management techniques and tactics as well as the use of modern technologies. Among the negative effects imposed, we can mention things such as capital wastage (increase in cost), increase in construction time, and at the same time decrease in quality. At the same time, all construction management activities, based on the contract documents, depend on the two categories of plans and project specifications. In the traditional methods of construction management, various executive plans such as structural, architectural and facility plans are prepared separately but in coordination with each other. These maps are two-dimensional and even if three-dimensional maps are prepared from them, the system will not be able to identify mistakes, interferences and changes. The purpose of this article is to examine the relationship between building information modeling and precast concrete structures and the implementation of that system in precast concrete structures.

Feasibility Study of Capacitor-Based Smart Washer Sensor Systems for Highway Sign, Luminaire/Light, and Traffic Signal Structures

This paper aims to provide an improvement on the current inspection methods for anchor bolts used in highway sign, luminaire/light, and traffic signal (SLTS) support structures to reduce the risk of structural failure as well as human labor costs. A feasibility study on a capacitance-based smart washer system was conducted. The capacitor-based sensor system design combined with customized polylactic acid three-dimensional printed attachments was proposed and tested. Laboratory tests on multiple sets of sensors were performed through initial testing and tightening–loosening testing; results have shown that the performance of the sensor system follows the working principle of the capacitor and, with a less than 5% error tolerance, a capacitance–pretension relationship was developed in the laboratory. Then the sensor system was installed at a sign structure specimen for long-term evaluation; the 12-month consecutive monitoring results show that the sensor system was able to perform steadily with a proper waterproof cover applied. The change of the capacitance was found at ±5% of the reference value, and torques were applied to verify the measurement results from the sensor system, indicating that the minor capacitance change was caused by a change of temperature. The results have proven the feasibility of this capacitor-based smart washer system that detects the pretension change inside the anchor bolts and performs steadily in a controlled on-site environment with a high durability. In summary, this study provides the possibility of improving the monitoring methods for anchor bolts in highway SLTS structures.

Структурный подход к оценке работоспособности системы мониторинга инженерных конструкций вантового моста через Петровский канал в створе автомобильной дороги «Западный скоростной диаметр» в городе Санкт-Петербурге. Часть 2

Purpose: assessing the performance of the monitoring system for engineering structures and assessing the current state of the structures of the cable-stayed bridge across the Petrovsky Canal in the alignment of the Western High-Speed Diameter highway in the city of St. Petersburg due to the occurrence of emergency situations in which accelerometers on the pylons record values exceeding the limit. Methods: statistical data from the databases of the existing system of monitoring engineering structures is used to obtain the results. The tasks, set within the framework of the study, are accomplished by applying the theoretical methods of scientific knowledge: the analytical method, the mathematical statistics theory, induction. Results: the resulting structural approach to assessing the performance of the monitoring system for engineering structures on cable-stayed bridges makes it possible to reduce the number of false alarms of the system and assess the current state of the bridge structure. Within the framework of the III stage of the structural approach, it is proposed to develop a methodology for assessing the performance of the monitoring system for engineering structures with subsequent assessment of the current state of cablestayed bridge structures. Practical significance: the results of the work are important for construction as they expand the understanding of the features of the mechanism of soil freezing.

Numerical and Experimental Study of Seismically Excited Scaled Structure with Active Mass Damper

In recent years, the development and implementation of artificial intelligence (AI) have attracted tremendous attention. The implementation of active control systems for building structures can be improved by using an AI controller. Non-AI controllers such as the Linear Quadratic Regulator (LQR) controller require full state variables of the structure to be measured, which is rarely feasible. To address this problem, two AI models, namely, artificial neural network (ANN) and fuzzy logic (FL), have been tried as AI-based controller in various studies. In the present study, both AI models were investigated to see their practicality and effectiveness. The AI models were implemented to control an active mass damper (AMD) in a three-story prototype-sized building. The simulation results from the structure with an LQR controller were used as benchmark and training data for the AI models. The results of the study demonstrated that although both AI models could reduce the structure responses, ANN was more practical and effective compared to FL as an AI-based controller for the given structure. Furthermore, the effectiveness of an ANN-based AMD was also shown by the experimental results.

Synergistic Effects of Liquid Rubber and Thermoplastic Particles for Toughening Epoxy Resin

This study aims to investigate the toughening effects of rubber and thermoplastic particles on epoxy resin (EP), and to understand the mechanism underlying their synergistic effect. For this purpose, three EP systems were prepared using diglycidyl ether of bisphenol-A (DGEBA) epoxy resin (E-54) and 4,4-Diamino diphenyl methane (Ag-80) as matrix resin, 4,4-diaminodiphenyl sulfone (DDS) as a curing agent, and phenolphthalein poly (aryl ether ketone) particles (PEK-C) and carboxyl-terminated butyl liquid rubber (CTBN) as toughening agents. These systems are classified as an EP/PEK-C toughening system, EP/CTBN toughening system, and EP/PEK-C/CTBN synergistic toughening system. The curing behavior, thermal properties, mechanical properties, and phase structure of the synergistic-toughened EP systems were comprehensively investigated. The results showed that PEK-C did not react with EP, while CTBN reacted with EP to form a flexible block polymer. The impact toughness of EP toughened by PEK-C/CTBN was improved obviously without significantly increasing viscosity or decreasing thermal stability, flexural strength, and modulus, and the synergistic toughening effect was significantly higher than that of the single toughening system. The notable improvement in toughness is believed to be due to the synergistic energy dissipation effect of PEK-C/CTBN.

Design and Optimization of Steel Structures for Solar Panel Systems

Abstract: Structural components are fundamental for supporting mechanical machines in industrial settings. These structures are designed not only to bear the weight of the machines but also to withstand the vibrations generated during operation. The project at hand focuses on integrating basic structural sections to create a complete mechanical framework. Our goal is to collaborate with an industry specializing in support structures for various electrical units. From our initial analysis, we observed that many of these industries rely on conventional manufacturing practices and past experience to design structures, often leading to overdesign. No finite element analysis (FEA) or theoretical calculations are typically applied. We propose introducing modern FEA techniques and concepts to optimize and refine these designs for improved efficiency.

Synthesis of metal(II) acetate complexes with a heterocyclic azo dye ligand: Characterization, geometrical molecular structures, antioxidant, biological activities, DNA binding and molecular docking studies

A series of Cu(II), Co(II), Ni(II), Mn(II), and UO2(II) complexes have been prepared from the ligand 4-(2’,4’-dihydroxybenzaldehyde phenylazo)antipyrine (H2L). FT-IR spectra demonstrated that the ligand under investigation behaves as a bi-and tridentate centre ligand through the phenolic oxygen of aldehydic, azo nitrogen atoms and carbonyl oxygen of antipyrine and forms a stable five- and six-membered chelating ring. From the X-ray crystallographic analysis (XRD) patterns of the ligand and complexes showed the polycrystalline phases are indicated by the multiple diffraction peaks in the 1igand and its complex (5). The HOMO‒LUMO energy gaps (∆E) were used to create theoretical models for the structure and confirmation barriers in molecular systems for the ligand (H2L) and metal complexes. It was found that the Cu(II), Co(II), Ni(II), and Mn(II) complexes have lower values for HOMO‒LUMO energy gaps (∆E), indicating that they are more stable than the 1igand. The biological activities of ligand (H2L) and its metal complexes showed that ligand was stronger antimicrobial and antioxidant agent than its metal complexes. 50 µg/ml H2L caused inhibition zones ranged from 13 to 20 mm against the tested bacteria and 13 to 16 against fungi. In addition, the present study tested metal (II) acetate complexes with a heterocyclic azodye ligand for their application in the textile industry as antimicrobial dyed fabrics. All obtained results confirmed the possibility of using the prepared compounds in different industrial applications. The 1igand (H2L) and its metal complexes showed moderate to strong antimicrobial activities in agar well diffusion, MIC, and antioxidant tests. Ligand and its metal complexes revealed inhibition zones against all tested microbes ranged between 6 to 24 mm. The MIC values of ligand and its metal complexes were recorded at 20 to 30 μg/ml and 30 to 145 μg/ml, respectively. 50 µg/ml of 1igand and its metal complexes was enough to complete inhibit Gram negative E. coli moreover they could inhibit the multidrug resistant bacteria K. pneumoniae and Pseudomonas sp. By molecular docking study, it was found that the complex (1) showed the highest and better binding affinity (-8.38874 and -7.74442 kcal/mol) than other 1igand (H2L) and complexes (2–5) for the breast cancer (3HB5) protein central activity and the colon cancer (2HQ6) protein central activity.

Binding properties of synthesized CS glasses activated by alkaline components

The paper presents the synthesis and evaluation of hydration and binding properties of individual minerals with glass-like structures in silicate systems, most often found in technogenic materials based on phosphorus and blast furnace slags. This work aims to determine the optimum composition of CS glasses to obtain binders with given properties, the hydration of glasses of different silicate and aluminosilicate compositions in the presence of solutions of soda, sodium hydroxide, and sodium metasilicate was investigated. The results of X-ray phase and differential-thermal analysis, and infrared spectrum are given, and the hydration structure of the calcium oxide-silicon oxide-alkali component system has been studied. The analysis of hydrate neoplasms of the studied binding systems shows that the most optimal conditions for the synthesis of stone strength with stable physical and mechanical properties are created in the presence of gel-like phase reinforced by hydrosilicates and hydroaluminosilicates of alkaline and alkaline-alkaline-earth composition, characterized by fiber-like structure and possessing the ability to epitaxial fusion with each other, as well as gel-like phase, which they reinforce.

Sliding Mode and Super-Twisting Sliding Mode Control Structures for Vertical Three-Tank Systems

Sliding Mode and Super-Twisting Sliding Mode Control Structures for Vertical Three-Tank Systems

Three stable nitrogen-rich Ce-N compounds predicted from first-principles calculations at high pressure

As a new type of environmentally friendly high energy density material, metal-doped nitrogen-rich compounds have drawn much attention in recent years in the field of scientific research due to their unique high pressure properties. In this paper, a first principle computational approach has been used to conduct an extensive structural search for energetically favorable structures in the Ce-N system. We finally discovered three new structures: Ce2N3 in the P21/m phase, CeN3 in the C2/m phase, CeN5 in the P phase. Among them, the C2/m-CeN3 structure remains kinetically stable at 0 GPa and can be quenched to ambient conditions after synthesis at high temperatures and pressures. The C2/m-CeN3 and P1¯-CeN5 compounds, which have significantly higher detonation velocities and pressures than TNT and HMX, can be used as potential energy materials. Their structures of P21/m-Ce2N3, C2/m-CeN3 and P1¯-CeN5 were successfully predicted, providing valuable references for synthesizing and exploring novel stable cerium-nitrogen compounds.

Mechanical force-switchable aqueous organocatalysis

Control over the catalytic activity of artificial catalytic systems in aqueous media is of high interest for biomimetic artificial catalysts. The activity of catalytic systems can be controlled via introducing stimuli-responsive feature in the structure of the catalytic systems. However, temperature, pH or light have been predominantly used as stimulus. Aqueous catalytic system whose activity can be turned ‘ON/OFF’ employing mechanical force has not been demonstrated. Here we show how catalytic activity of an aqueous catalytic system can be switched ‘ON/OFF’ via the application/ceasing ultrasound stimulus. We demonstrate that the accessibility of imidazole, a catalyst moiety, can be modulated via the presence/absence of the ultrasound stimulus, resulting temporal control over the rate of ester hydrolysis reactions in aqueous buffer solution. This generic approach enables using a large range of organocatalysts for the preparation of molecules and/or materials in aqueous media for their application to material science, and in biomedical field.

State Estimation of Radial Distribution Systems Based on Multiple Legendre Neural Networks

The conventional weighted least square (WLS) method is the most effective technique used in the state estimation of high voltage transmission system. Unfortunately, the application of WLS in radial distribution network encounter difficulties due to the inherent characteristics of these systems, such as the low measurement redundancy and high r/x ratio of the distribution systems. Given the structure of bulky systems that require a bulky number of measurements, the use of artificial neural networks is considered an effective alternative to estimate these values using a lesser number of measurements than conventional techniques. Due to state estimation based on ANN technique, the time-consuming gain matrix manipulation and pseudo measurements required in the conventional WLS method are no longer necessary. The efficiency of deep learning neural networks such as multi-layer perceptron (MLP) and Legendre neural network (LeNN) depends on the position of the measurements and the number of neural networks applied. Determining the applicable number of neural networks to ensure high estimation accuracy plays an important role in the estimation process. This aspect is addressed in this study, where multiple neural networks are used to improve performance compared to a single neural network. The results obtained indicate that determining the applicable number of neural networks depends on several factors such as the position of the measurements and the diversity of the data. The application of LeNN on state estimation of a 69-bus radial distribution network is used as an illustrative example to explain the distinctive feature of the proposed technique.

Diseño y análisis dinámico de un edificio multifamiliar de 4 niveles sin sótano en la Provincia de Chanchamayo

In the present investigation, the design of a 4-story building without a basement located in the Province of Chanchamayo of Peru was carried out, intended for a multi-family home made up of structural elements such as columns, beams, and plates, which each one was designed and modeled under the Peruvian Load Regulations E. 020, Earthquake-resistant Design E. 030, Reinforced Concrete E. 060, Masonry E. 070 and General Design Conditions A. 010. The use of these Standards is established in the National Building Regulations that allowed compliance with the objective of designing and carrying out the Dynamic Analysis of the Building under the Earthquake methodology, which is based on the Load factor and resistance design method. Modeling was carried out with the help of ETABS software to obtain results necessary for the design and analysis of the structure. Finally, it was obtained that the building will use the structural system for structural walls, which has a basic reduction coefficient equal to 6 and it is concluded that the methodology used allows guaranteeing the safety, functionality and quality service of a building.

Seismic Risk Evaluation of Existing Reinforced Concrete Buildings: A Case Study for Çanakkale-Türkiye

Türkiye is in an important earthquake zone, and most of the population is under seismic hazard. The high loss of lives in the past earthquakes indicates that our existing building stock is vulnerable. In this study, a field survey was carried out to determine the existing earthquake risks of reinforced concrete buildings in İsmetpaşa, Barbaros, Cevatpaşa, Kemalpaşa, Namıkkemal, Esenler, and Fevzipaşa Neighborhoods of Çanakkale city center. This study was conducted to specify the regional distribution of risky buildings to be examined by the street survey method called "Simplified methods that can be used to determine the regional risk distribution of buildings" in the implementation regulation of Law No. 6306. For this purpose, 585 reinforced concrete buildings were examined with this method, and the earthquake performance scores of these buildings were determined. The performance scores calculated as a result of reflecting the number of stories, earthquake hazard zone, type of structural system, and structural irregularities of the buildings were evaluated based on different parameters. It was seen that soft stories with values ranging from 50% to 100% and heavy overhangs with values ranging from 37% to 63% were the most common irregularities in existing buildings in Çanakkale.

Parametric optimization of SIP connection geometry in CFS-MRF structures: A finite element study

The structural buildings should be designed to resist both static and dynamic loads. There are different types of structural systems that can support seismic loads. Moment-resisting frames (MRFs) are widely used for seismic purposes, relying on the plastic deformations occurring between the beam and column. The main problems of cold-formed steel sections in MRFs during seismic loads are premature local and distortional buckling, which cause severe damage under strong earthquakes, such as early loss of connection strength, low ductility, and low energy dissipation. This paper clarifies the performance of the CFS section with steel interconnected part (SIP) in moment-resisting frames (MRFs) in many aspects using finite element (FE) procedures. The study summarizes the required dimensions of SIP to achieve optimal behavior for the beam-column connection. Additionally, an advanced connection consisting of SIP and four pairs of out-of-plane stiffeners has been examined. The locations of the out-of-plane stiffeners have been carefully selected to stabilize the connection. A cantilever beam connection has been used to represent an MRF in an advanced way. The connection consists of 2 C channel back-to-back beams connected with a through plate with sixteen bolts. Numerical models have been developed and verified with experimental tests under both monotonic and cyclic loading. The characteristics and creation of the numerical model are well illustrated in this paper. Cyclic loading has been applied according to AISC protocol, which is used to test the performance of the steel connections, as well as to classify the connection according to different design codes. The results show that increasing the plastic moment capacity of the CFS section decreases the required SIP dimensions to achieve optimal behavior by the connection. Additionally, it has been found that using out-of-plane stiffeners in particular locations with SIP increases energy dissipation on average by 74 %. Using stiffeners with SIP can upgrade the classification of the connection from an ordinary or intermediate moment connection to a special moment connection without the need to increase the CFS cross-section area or reduce the slenderness ratio, which in turn reduces the overall costs of construction.

PSYCHOLOGICAL SUPPORT OF THE DEVELOPMENT OF THE REHABILITATION POTENTIAL OF EMPLOYEES OF THE FORCE

The article the main approaches to the psychological support of the process of development of rehabilitation potential of specialists of law enforcement agencies. The purpose of our article is to study the peculiarities of social functioning and the leading factors of mental trauma in specialists of law enforcement agencies with depressive disorders of neurotic origin. During the research, the following methods were used: analysis of special, scientific and methodological literature, analysis of documentary materials, observation, testing, experiment, methods of mathematical statistics. Factors of development of rehabilitation potential of personality are characterized. The peculiarities of the systemic structure of mental phenomena and the concept of psychological support of the process of development of rehabilitation potential are considered. The need to implement a systematic approach based on empirical data, which includes research aimed at harmonizing the psychological state of law enforcement officers, is emphasized. Empirical research has revealed the peculiarities of the social functioning of specialists in law enforcement agencies with depressive disorders of neurotic origin. There are differences in the psychological well-being of professionals with depressive disorders of neurotic origin and people without mental disorders, namely: people without mental disorders are characterized by a predominance of interest in life, reflecting their interest in everyday life, enthusiasm for what is happening; in people with mental disorders, the indicators of "consistency in achieving goals" and "consistency between goals and their achievement" are such that indicate inadequate assessment and inability to use their own strength to achieve the goal.

The Time Series Classification of Discrete-Time Chaotic Systems Using Deep Learning Approaches

Discrete-time chaotic systems exhibit nonlinear and unpredictable dynamic behavior, making them very difficult to classify. They have dynamic properties such as the stability of equilibrium points, symmetric behaviors, and a transition to chaos. This study aims to classify the time series images of discrete-time chaotic systems by integrating deep learning methods and classification algorithms. The most important innovation of this study is the use of a unique dataset created using the time series of discrete-time chaotic systems. In this context, a large and unique dataset representing various dynamic behaviors was created for nine discrete-time chaotic systems using different initial conditions, control parameters, and iteration numbers. The dataset was based on existing chaotic system solutions in the literature, but the classification of the images representing the different dynamic structures of these systems was much more complex than ordinary image datasets due to their nonlinear and unpredictable nature. Although there are studies in the literature on the classification of continuous-time chaotic systems, no studies have been found on the classification of discrete-time chaotic systems. The obtained time series images were classified with deep learning models such as DenseNet121, VGG16, VGG19, InceptionV3, MobileNetV2, and Xception. In addition, these models were integrated with classification algorithms such as XGBOOST, k-NN, SVM, and RF, providing a methodological innovation. As the best result, a 95.76% accuracy rate was obtained with the DenseNet121 model and XGBOOST algorithm. This study takes the use of deep learning methods with the graphical representations of chaotic time series to an advanced level and provides a powerful tool for the classification of these systems. In this respect, classifying the dynamic structures of chaotic systems offers an important innovation in adapting deep learning models to complex datasets. The findings are thought to provide new perspectives for future research and further advance deep learning and chaotic system studies.

Technical aspect of the operation of accelerometers as composition of a system for monitoring engineering structures of a cable-stayed bridge over the Petrovsky canal in the construction of the Western Speed Diameter highway in Saint Petersburg

Aim. This study analyzes the current monitoring system for the engineering structures of a cable-stayed bridge across the Petrovsky Canal, part of the Western High-Speed Diameter highway in St. Petersburg, focusing on emergency situations where accelerometers on pylons record values that exceed limits. Methods and Materials. The study utilizes statistical data from existing monitoring system databases. The tasks, set within the framework of the study, are accomplished by applying theoretical scientific methods including analytical techniques, mathematical statistics, and induction. Results. The analysis presents an overview of the current system used for monitoring engineering structures and highlights issues related to emergency situations in which accelerometer readings exceed threshold values. This study proposes a method for assessing the reliability of the monitoring system by classifying the data obtained from the accelerometer into two groups. The research identifies the need for further investigations to understand the root causes of these issues. Conclusion. Тhe results can assist in the design and installation of monitoring systems of the engineering structures for cable-stayed bridges, as well as for modernization and optimization of existing monitoring systems to improve the quality of structural technical condition assessments.

Structure, properties, and decomposition in biological systems of a new nitrosyl iron complex with 2-methoxythiophenolyls, promising for the treatment of cardiovascular diseases

A new promising binuclear tetranitrosyl iron complex with 2-methoxythiophenolyl of the composition [Fe2(C7H7OS)2(NO)4] (complex 1), which acts on the therapeutic targets of cardiovascular diseases, guanylate and adenylate cyclase, has been synthesized. X-ray diffraction data show the presence of two isoforms of complex 1; according to quantum chemical calculations, the structure of only the trans isomer is stable in solutions.The processes of transformation of complex 1 in DMSO, in aqueous solutions, as well as in the presence of bovine serum albumin, reduced glutathione, and mucin were studied. DMSO promotes the decomposition of the original complex 1 into mononuclear products. In biological systems, the mechanisms of decomposition of the complex 1 differ from aqueous solutions. In albumin solution, a gradual formation of a high-molecular-weight dinitrosyl complex is observed, obtained by coordinating the [Fe(NO)2]+ fragment with the amino acid groups of the protein. In the presence of mucin, an EPR signal from stable mononitrosyl products is observed. The introduction of glutathione into the system of the complex 1 leads to the replacement of one initial thioligand with glutathione. In the model systems under study, a more efficient and prolonged generation of NO groups is observed compared to a buffer solution.The obtained data on the influence of the environment on the properties of the complex 1 in combination with a study of their effect on enzymes allow us to recommend it for further study as a potential drug with vasodilator, antianginal, and hypotensive properties.

20 years of monitoring of a steel jacket offshore platform: variability of environmental and modal parameters

The fixed steel offshore platform VEGA-A has been operating in the Sicily channel since 1988. The platform, one of the largest in the Mediterranean Sea, is equipped with a monitoring system that collects environmental (by means of a current meter, a depth gauge, and a system for detecting wind speed and direction) and structural (by means of nine accelerometers) data. After a description of the recording system, this paper provides a statistical interpretation of the structural response of the platform over the last 20 years. The structural monitoring system is aimed at performing dynamic identification (i.e., evaluating main frequencies and mode shapes), and part of the acquired data is directly processed on the platform in order to constantly check their representativeness in relation to the structural control of the platform. The possible variation of main frequencies and mode shapes over time may be due to both changes in environmental loads/conditions and/or structural damage; in this respect, a data-driven approach capable of recognizing anomalies in the dynamic behavior was adopted here to assess the performances of the platform over the 20 years monitoring period.