T-shaped Model Research Articles

High-Cycle Fatigue Crack Growth in T-Shaped Tubular Joints Based on Extended Finite Element Method

High fatigue load, which exists widely in steel building structures, likely leads to brittle failure at the joints, supports, and so on. This can lead to the partial or total damage of the structure and even to cause the collapse of the whole structure. This article aims to provide a method to simulate high-cycle crack propagation in tubular joints, which is one of the most common types occurring in steel structures. Firstly, sixteen T-shaped tubular joint models under different load conditions and initial crack dimensions were built through the coordinate mapping method. Secondly, based on the extended finite element method (XFEM), an algorithm was developed by combining the secondary development in Abaqus and a quasistatic simulation method to simulate high-cycle crack growth in tubular joints under a constant amplitude. The results of the simulations were compared with experimental data. The study found that the surface stress calculated from the tubular joint models using the coordinate mapping method was close to the experimental data. Through the comparison of the crack propagation rate and the crack growth process between the simulation and experiment results, the simulation method was validated. When a crack penetrated the tube wall, the difference in the load cycles between the simulations and the experiment was 9.5%. The initial crack dimension had an impact on the crack propagation, with the decrease in the a/c and KII generally becoming the dominant factor with respect to the crack growth, while the fatigue life of the joints tended to increase.

Equivalent circuit of a planar microwave liquid sensor based on metamaterial complementary split ring resonator

Abstract In the present work, a study of a metamaterial complementary split ring resonator (CSRR) microwave planar sensor for dielectric liquid characterization is carried out using HFSS software. The design consists in a CSRR-loaded two ports rectangular patch microstrip-fed grounded planar structure. The investigated liquid sample is put in a capillary glass tube lying parallel to the surface of the sensor. The liquid test tube is deposited horizontally parallel to the surface of the planar sensor. The advantage of the design lies on the fact that it allows different orientations and multiple size possibilities of the test tube. This makes it possible to explore different resonant frequencies in the 2.1 GHz frequency band. Moreover, an optimization study is carried out to achieve a high sensitivity and a high-quality factor of the proposed sensor. To better understand the operation and to further verify the feasibility of the equivalent circuit, a parallel RLC resonant circuit is used to obtain the desired Z parameter responses Z 11, Z 22, Z 21. A T-shaped electrical model of the proposed sensing structure is established using Advanced Design System (ADS) software. This latter constitutes one of the principal novelties of this work, which has never been addressed so far.

Validation of model-based design of experiments for continuous wet granulation and drying

This paper presents an application case of model-based design of experiments for the continuous twin-screw wet granulation and fluid-bed drying sequence. The proposed framework consists of three previously developed models. Here, we are testing the applicability of previously published unit operation models in this specific part of the production line to a new active pharmaceutical ingredient. Firstly, a T-shaped partial least squares regression model predicts d-values of granules after wet granulation with different process settings. Then, a high-resolution full granule size distribution is computed by a hybrid population balance and partial least squares regression model. Lastly, a mechanistic model of fluid-bed drying simulates drying time and energy efficiency, using the outputs of the first two models as a part of the inputs. In the application case, good operating conditions were calculated based on material and formulation properties as well as the developed process models. The framework was validated by comparing the simulation results with three experimental results. Overall, the proposed framework enables a process designer to find appropriate process settings with a less experimental workload. The framework combined with process knowledge reduced 73.2% of material consumption and 72.3% of time, especially in the early process development phase.

A study of the optimal form and orientation for more energy efficiency to mass model multi-storey buildings of Kirkuk city, Iraq

Efficient use of Energy and the usage of renewable forms of energy are considered to be key concepts of sustainable architectural design. Our country, Iraq, including the city of Kirkuk, is one of the developing cities that witnessed an increase in the population and thus the expansion of the city, and due to the lack of local studies in the field of sustainability and energy efficiency, the need for research in the field of applying these concepts in designing buildings to save local energy has emerged.This study examines the potential for sustainable architectural design in the city of Kirkuk, Iraq. The research specifically focuses on analysing the environmental performance of a ten-story multi-storey building to determine the optimal form and orientation that would minimise energy consumption and yield environmental and economic benefits. Building Information Modelling (BIM) and simulation were used to evaluate the energy consumption of six different building models over a 12-month period. Results indicate that the T-shaped model had the lowest energy consumption at a rotation angle of 285˚, providing valuable insights for the design and construction of energy-efficient buildings in Kirkuk.

TRAINING OF FUTURE LOGISTICS AND SUPPLY CHAIN MANAGERS: A COMPETENCY APPROACH

The paper highlights the results of scientific research on the issues of training highly qualified logistics and supply chain managers, justification of directions, and development of practical mechanisms for its improvement.The paper is based on scientific literature analysis, comparative analysis, and case study research.It is established that modern global trends and changes in society and the economy lead to the emergence of more extended requirements for the training of highly qualified managers able to effectively perform specific types of work in accordance with the needs of society and the labour market in the field of logistics and supply chain. In this context, the issues of applying a competency approach when training future logistics and supply chain managers and the formation of a competency model that meets the modern requirements of the labour market are considered. A review of scientific literature has been carried out regarding the main theoretical foundations of forming competences and competencies in the process of professional training of logistics and supply chain managers. Attention is focused on the need to form basic core competencies, including models of basic professional competences and competencies that are key ones in the professional activity of specialists. The main models of competencies of the company's specialists, which make it possible to ensure effective management of modern companies, are highlighted. The experience of training future logistics and supply chain managers in Ukraine is studied. The expediency of applying a competency approach when training future logistics and supply chain managers in Ukraine is substantiated. A conceptual model of a multi-level national system of professional training of logistics and supply chain specialists is proposed. A T-shaped model of the competencies of modern logistics and supply chain managers is developed.

Clinical Psychologists as T-Shaped Professionals

The modern world is becoming increasingly integrated, and disciplines are frequently collaborating with each other. Following this trend, clinical psychologists are also often working within multidisciplinary teams and in settings outside of traditional mental health. To be competent and effective in these contexts, clinical psychologists could benefit from skills outside of psychology. The current psychology training model provides depth of training in psychology but could be improved by providing the breadth of training required of modern clinical psychologists working in these contexts. Other disciplines, such as engineering, business, and social work, have improved their breadth of training through the adoption of the T-shaped model. This model of training allows individuals to simultaneously acquire the depth of knowledge required for their discipline and the breadth required to work effectively in multidisciplinary contexts. This article discusses areas in which clinical psychologists could benefit from broad training and recommendations to implement the T-shaped model.

Accuracy of Seismic Response Evaluation of Two-Dimensional Analysis Model with Rigid Joints for RC Frame Buildings.

Three- or two-dimensional (2D) numerical models are used for the evaluation of the seismic performance of reinforced concrete (RC) buildings. This study examines a 2D numerical model for a specimen used in a full-scale four-story RC shaking-table test and evaluates the accuracy of the seismic response of the 2D numerical model, which is composed of a square fiber section model for the columns, a T-shape fiber section model for the beam and slab, and a rigid joint model for the beam-column joint. A parametric analysis of the effective slab width is performed to analyze its effects on the modal shape and natural period. The results suggest that the primary natural period of the considered model is almost identical to that associated with the experimental results. The applicability of the 2D numerical model for estimating the seismic response of the structure is established. By comparing the results of the seismic analysis and the experiment in the 50% amplitude of the JMA-Kobe wave, which corresponds to slightly exceeding VII on the modified Mercalli intensity scale, the root-mean-square percentage error of the 2D numerical model is 1.03% for the floor acceleration and 4.7% for the inter-story drift. Thus, the analytical model used in this study has sufficient accuracy in evaluating the seismic performance of buildings constructed in regions with a maximum seismic intensity of VII.

Building T-shaped professionals for mastering digital transformation

Digital transformation is a multidimensional challenge that is requiring to change consolidated approaches and managerial models. New organized entities are emerging because of this ongoing transformation and new competences are required for managing and living them. Thanks to the interpretative contribution provided by the systems thinking, the paper focuses the attention on the paradigm shift required for defining t-shaped professionals able to master digital transformation in emerging dynamics. A conceptual model is proposed and discussed building upon the T-shaped model with the aim to enrich current theoretical and managerial debates about strategies for supporting both individuals and organizations in facing the challenges imposed by the digital transformation.

Wind loads characteristics of irregular shaped high-rise buildings

Many irregular shaped high-rise buildings have been built for graceful demand of architecture or better amenity and ventilation in the world. In this study, a benchmark rectangular high-rise building model and six high-rise building models with various irregular shapes, including two T-shaped, two U-shaped, H-shaped and X-shaped, are tested in a boundary wind tunnel to investigate their wind loads characteristics. The coefficients, power spectral density and cross-correlation of base moments as well as local wind forces are analyzed and discussed in details. Based on the wind tunnel test results, it is founded that the effect of U-shape and H-shape on wind loads is negligible. The along-wind mean base moment coefficient of X-shaped model is increased by 10.0% in 90° wind direction. The wind force characteristics of T-shaped models are quite different from the benchmark model in many cases. The mean base moment coefficient of T-shaped 2 model is reduced by 18.6% in 0° wind direction. Larger mean lift forces and torques of T-shaped models are appeared and there is a certain correlation between along-wind and across-wind local wind forces in 90° wind direction.

Numerical Study of Wind induced Pressures on Irregular Plan Shapes

Purpose: This paper presents the numerical examination of wind pressure distributions on irregular plan shape building models over wind incidence angles of 0° and 180°. The purpose of this study is to investigate the effect of irregular building form, projection ratios, distances from the re-entrant corner, the building height and wind incidence angles on the wind flow and wind pressure distributions at all surfaces of the buildings.Design/Methodology/Approach: Two L-shaped and two T-shaped building models having the same plan area and height but having different projections in plan were analyzed by the application of Computational Fluid Dynamics (CFD) package of ANSYS. With this purpose, wind pressure distributions on and around various irregular plan shaped buildings are analysed for the same height level.Findings: As a result of the studies, it has been observed that the plan shape, projection ratios, distances from the re-entrant corner, significantly affect the wind characteristics on building.Research Limitations: In recent years, numerical approaches based on computational fluid dynamics (CFD) simulations are being commonly used engineers and architects for various wind studies such as determining wind loads on buildings and investigating wind flows in built area. Model dimensions were reduced to 1/100 scale to save computing time.Practical Implications: Understanding the behavior of the building under the wind load will increase the solution oriented approach to the problems at the initial part of the design stage.Social Implications: The study supports occupant comfort by making it easier to perceive the design component wind in the architectural sense.Originality/Value: Wind is a significant architectural design component. However, there are very few studies on wind behavior of buildings in the architectural field. This is often observed as an engineering problem. On the contrary, it is primarily an architectural design piece to be perceived. Therefore, understanding the behavior of buildings under wind loads is vital to develop problem-oriented solutions at every stage of the design phase. Projections in plan with different wind angle and distances from the re-entrant corner’s effect on pressure coefficients were not be studied comprehensively. Key Words: Building form, building dimensions, projections, mean wind pressure coefficient, computational fluid dynamics (CFD

Quantitative Evaluation of Unfilled Grout in Tendons of Prestressed Concrete Girder Bridges by Portable 950 keV/3.95 MeV X-ray Sources

We have developed porTable 950 keV/3.95 MeV X-band (9.3 GHz) electron linear accelerator (LINAC)-based X-ray sources and conducted onsite prestressed concrete (PC) bridge inspection in the last 10 years. A T-shaped PC girder bridge with a thickness of 200–400 mm and a box-shaped PC girder bridge with a thickness of 200–800 mm were tested. X-ray transmission images of flaws such as thinning, fray, and disconnection caused by corrosion of PC wires and unfilled grout were observed. A three-dimensional structural analysis was performed to estimate the reduction in the yield stress of the bridge. In this study, we attempted to evaluate the unfilled grout quantitatively because it is the main flaw that results in water filling and corrosion. In the measured X-ray images, we obtained gray values, which correspond to the X-ray attenuation coefficients of filled/unfilled grouts, PC wires (steel) in a sheath, and concrete. Then, we compared the ratio of the gray values of the filled/unfilled grouts and PC wires to determine the stage of the unfilled grout. We examined this quantitative evaluation using the data obtained from a real T-shaped PC girder bridge and model samples to simulate thick box-shaped PC girder bridges. We obtained a clear quantitative difference in the ratios for unfilled and filled grouts, which coincided with our visual perception. We synthesized the experience and data and proposed a quantitative analysis for evaluating the unfilled grout for subsequent steps such as structural analysis and destructive evaluation by boring surveys.

The emergence of new market spaces: Brokerage and firm cognitive endowment

Framing within the service-dominant logic view, this paper deals with the emergence of new market spaces conceptualized as new contexts of use. This work aims to describe the emergence of a new value cocreation context from brokerage and exaptation strategies. By filling a literature gap, the paper describes why and how the service-dominant logic and brokerage strategy, i.e., a strategy brokering different cultural domains and contexts of use, and their variant exaptation, i.e., a strategy brokering a technological domain featured by a specific use with a completely different context of use, are useful for framing the emergence of a new market space. The paper's second aim is to draw the configuration of firm cognitive endowment—the T-shaped model—potentially enabling brokerage/exaptation strategies. The paper highlights the features a firm cognitive endowment should possess in terms of in-depth competencies and dynamic capabilities to trigger new and potentially valuable contexts of use.

Re-positioning SoTL toward the T-shaped Community

Amongst a range of changes that have taken place within tertiary education, perhaps the most revolutionary has been a shift to student-centred approaches focused on life-long learning. Accompanying this approach to holistic higher education (HE) has been a growing interest in, and understanding of, the Scholarship of Teaching and Learning (SoTL). SoTL has, at its core, a deep concern with student learning and is therefore well-aligned with higher education’s renewed focus on its students. In this conceptual paper, we examine the impact of the T-shaped person which many tertiary institutions are operationalizing to inform and connect the development of students’ deep disciplinary knowledge with non-academic and employment readiness skills (such as communication, problem-solving, teamwork, and critical thinking). Importantly, we argue for a re-positioning of SoTL to complement and support this model, with SoTL as both the fulcrum and the fluid, multiple threads of discourse that are intricately entwined around the structure of the T-shaped model. We encourage our colleagues to strive to be T-shaped practitioners and we cast a vision of a T-shaped community. Here, all stakeholders within HE connect both their academic knowledge and holistic skills in collaborative ways to produce learners who flourish in modern society. The SoTL community plays a pivotal role in achieving this vision and is well-positioned to expand the current notion of SoTL toward a more holistic, interconnected, central role in HE.

Re-positioning SoTL toward the T-shaped Community

Amongst a range of changes that have taken place within tertiary education, perhaps the most revolutionary has been a shift to student-centred approaches focused on life-long learning. Accompanying this approach to holistic higher education (HE) has been a growing interest in, and understanding of, the Scholarship of Teaching and Learning (SoTL). SoTL has, at its core, a deep concern with student learning and is therefore well-aligned with higher education’s renewed focus on its students. In this conceptual paper, we examine the impact of the T-shaped person which many tertiary institutions are operationalizing to inform and connect the development of students’ deep disciplinary knowledge with non-academic and employment readiness skills (such as communication, problem-solving, teamwork, and critical thinking). Importantly, we argue for a re-positioning of SoTL to complement and support this model, with SoTL as both the fulcrum and the fluid, multiple threads of discourse that are intricately entwined around the structure of the T-shaped model. We encourage our colleagues to strive to be T-shaped practitioners and we cast a vision of a T-shaped community. Here, all stakeholders within HE connect both their academic knowledge and holistic skills in collaborative ways to produce learners who flourish in modern society. The SoTL community plays a pivotal role in achieving this vision and is well-positioned to expand the current notion of SoTL toward a more holistic, interconnected, central role in HE.

Biomechanical and adhesion comparison of linea alba prophylactic reinforcement with coated and uncoated three-dimensional T-shaped mesh in rabbits.

Purpose:Incisional hernia (IH) is a frequent complication of median laparotomy. The use of prophylactic mesh to reduce IH incidence has gained increasing attention. We hypothesized that in an animal model, linea alba prophylactic reinforcement with a three-dimensional T-shaped polypropylene mesh results in greater abdominal wall resistance.Methods:Study was performed in 27 rabbits. After abdominal midline incision, animals were divided into three groups according to the laparotomy closure method used: (1)3D T-shaped coated mesh; (2)3D T-shaped uncoated mesh; and (3) closure without mesh. After 4 months, each animal’s abdominal wall was resected and tensiometric tests were applied. Results included IH occurrence, adhesions to the mesh, and wound complications.Results:There was no significant difference between the groups in maximum tensile strength (p=0.250) or abdominal wall elongation under maximum stress (p=0.839). One rabbit from the control group developed IH (p=1.00). Small intestine and colon adhesions occurred only in the uncoated mesh group (p<0.001) and the degree of adhesions was higher in this group compared to the coated mesh group (p<0.05).Conclusion:Use of the current 3D T-shaped prophylactic mesh model did not result in a significant difference in tensiometric measurements when compared with simple abdominal wall closure in rabbits.

Influence of T-Shape Tip Clearance on Energy Performance and Broadband Noise for a NACA0009 Hydrofoil

In the present paper, the effect of the proposed T-shape tip on the energy performance, flow patterns and broadband noise sources of a NACA0009 hydrofoil with tip clearance is investigated. The vortex induced by the gap is simulated by means of the SST k-ω turbulence model, and then, the noise generated by dipoles and quadrupoles are analyzed by using the Curle acoustic analogy and Proudman acoustic analogy, respectively. The numerical simulation results agree well with the experimental measurements. Results indicate that three tip shapes, including the half pressure side T-shape model (MPT), the half suction side T-shape model (MST) and the T-shape model (MT), have complex influence on energy performance of the foil. Only the MST model can promote the energy performance of the hydrofoil at all inlet velocities, with the maximum ratio of lift coefficient to drag coefficient increasing by 4.26%. In addition, the ratio of lift coefficient to drag coefficient for MT obviously increases when the inlet velocity is 7.5 m/s, 10 m/s, 12.5 m/s and 15 m/s, and the maximum promotion is 15.21% at 7.5 m/s. The T-shape tip can effectively suppress the tip clearance leakage vortex, which makes the vortex area decrease with a maximum drop of 5.02%. Furthermore, the MPT and MT have good suppression effect on the hydrofoil dipole noise, and reduce the maximum Curle Acoustic Power (AP) of the foil with 2.64% and 3.03%, respectively. The MST model obviously reduces the isosurface area of the Proudman AP by 6.55% for 55 dB.

Experimental and numerical analysis on flow characteristics and pyrolysis mechanism of hydrocarbon fuel with a novel online hybrid method

A novel online hybrid method is developed to construct the reaction mechanism of hydrocarbon fuel by avoiding the overestimation of conversion and removing the measurement error of product composition. The validation of online hybrid technology is conducted by experimental measurement and numerical modeling. With enhancing heat transfer efficiency and rapidly annihilating radicals to terminate chemical reaction, the measurement results of the online cooling technology are more accurate and reliable than those of the tradition indirect contact cooling apparatus. The flow process, heat transfer, reaction characteristics and thermophysical properties of hydrocarbon fuel are investigated under various pressures and temperatures. The chemical reaction pathways and product distributions at the heating section are different from those at the connecting section, due to a high-temperature boundary layer in the heating section. Further, a 3D T-shape mathematical model embedded a molecular chemical reaction and fluid thermophysical properties is established to validate and analyze the extensive availability of the online hybrid method. A detailed performance analysis of the injecting coolant that acts to eliminate and elucidate the effect of subsequent reaction process is carried out to optimize operation conditions experimentally and numerically. As the increase of the coolant, the subsequent reaction process is gradually weakened until terminated. The gradients of temperature and concentration are formed by the injection of coolant and then the gradients are gradually diminishing to disappear along the connecting part due to the energy and mass transport.

BOLTED CONNECTIONS FOR NON-INTERSECTING H-SECTION BEAM AND COLUMN IN STEEL MOMENT FRAMES

This research proposes connection configurations of two types for non-intersecting H-section steel beam and column. To elucidate the mechanical behavior of the proposed connections, full-scale moment connection tests and finite element analyses were conducted using T-shaped partial frame models. Comparisons between the proposed connections and regular intersecting connections demonstrate that the proposed connection is able to provide sufficient stiffness and energy-dissipation capacity if the beam and column flanges are designed to provide sufficient shear resistance. Then to understand the global behavior of frames using the proposed connections, pushover analyses of a two-story two-span frame were conducted. Because the bending moment of the beam acts on the column by a torque through the proposed connections, torsion spring models were incorporated for representing the proposed connections in 3D frame analysis. Analysis results showed that the girders and columns exhibited lower stiffness and strength than those of frames with intersecting connections because of torsion. To overcome this issue, torsion restraint by secondary beams with different configurations was discussed and optimal configuration was suggested. By utilizing the optimal configuration, torsion of girders and columns can be efficiently reduced into a similar level as that of regular intersecting connections.

Design and simulation of a combined serpentine t-shape magnetorheological brake

A magnetorheological brake (MRB) is a device to dissipate rotational energy using magnetorheological fluids (MRF). MRB can change its braking torque quickly in response to external magnetic field strength. The brake is rotational, utilizing the MRF in shear mode. In this study, the geometrical design of the MRB, magnetic circuit and MRF flow path is addressed. Mathematical models are presented that describe the braking torque of the MRB. A novel prototype is introduced combining T-shape rotor model with serpentine flux magnetic circuit configuration. The rotor member is selected to direct the flux concentration at that location. Serpentine flux configuration is selected to achieve higher torque without increasing the size of MRB by activated more surface area of MRF with the magnetic flux. The finite element method is used to evaluate the magnetic flux density in MRB using FEMM 4.2. FEMM results showed that this novel design could provide sufficient magnetic flux along MRF flow path. Finally, the influence of input current to the MRB on braking torque is investigated. It is found that the braking torque in MRB increases with the increase of the input current. The prototype is formulated as foot-drop prevention orthotic. The MRB would be further integrated into ankle-foot orthoses for post-stroke patients. The design is formulated as a preliminary geometrical design, aiming to obtain the minimum required braking torque.

A novel plasmonic elliptical nanocluster and investigating Fano response in π- and T-shaped arrays

ABSTRACTFano resonance has been considered especially in nanostructures for energy enhancement and creating hot spots in nanoparticles based on plasmonic properties. In this paper, a novel arrangement of elliptical nanoantenna has been noticed for improving the electric field and energy enhancement in hot spots for mid-infrared range. For this, elliptical cylinders and elliptical rings are developed for dark mode by the concentration of plasmonic charges in a limited area, and the interaction between bright and dark mode has been used for the Fano shape of the extinction cross section. The combination of dipole arrangement has been implemented based on elliptical hollow cylindrical particles with various inner radios for arousing the Fano resonance. Finally, π- and T-shaped models are studied for Fano resonance, and the electric fields are compared in all cases. Exactly, this study is important for two main reasons: (1) it shows how we can control the extinction cross section and (2) it shows that by distortion for linear array the Lorentzian shape is changed to Fano shape.