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1 – 10 of over 29000Nasir Bedewi Siraj, Aminah Robinson Fayek and Mohamed M. G. Elbarkouky
Most decision-making problems in construction are complex and difficult to solve, as they involve multiple criteria and multiple decision makers in addition to subjective…
Abstract
Most decision-making problems in construction are complex and difficult to solve, as they involve multiple criteria and multiple decision makers in addition to subjective uncertainties, imprecisions and vagueness surrounding the decision-making process. In many instances, the decision-making process is based on linguistic terms rather than numerical values. Hence, structured fuzzy consensus-reaching processes and fuzzy aggregation methods are instrumental in multi-criteria group decision-making (MCGDM) problems for capturing the point of view of a group of experts. This chapter outlines different fuzzy consensus-reaching processes and fuzzy aggregation methods. It presents the background of the basic theory and formulation of these processes and methods, as well as numerical examples that illustrate their theory and formulation. Application areas of fuzzy consensus reaching and fuzzy aggregation in the construction domain are identified, and an overview of previously developed frameworks for fuzzy consensus reaching and fuzzy aggregation is provided. Finally, areas for future work are presented that highlight emerging trends and the imminent needs of fuzzy consensus reaching and fuzzy aggregation in the construction domain.
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This paper aims to investigate the responses of laminated glass under soft body impact, including elastic impact and fracture/fragmentation consideration.
Abstract
Purpose
This paper aims to investigate the responses of laminated glass under soft body impact, including elastic impact and fracture/fragmentation consideration.
Design/methodology/approach
The simulation uses the combined finite-discrete element method (FDEM) which combines finite element mesh into discrete elements, enabling the accurate prediction of contact force and deformation. Material rupture is modelled with a cohesive fracture criterion, evaluating the process from continua to discontinua.
Findings
Responses of laminated glass under soft impact (both elastic and fracture) agree well with known data. Crack initiation time in laminated glass increases with the increase of the outside glass thickness. With the increase of Eprojectile, failure mode is changing from flexural to shear, and damage tends to propagate longitudinally when the contact surface increases. Results show that the FDEM is capable of modelling soft impact behaviour of laminated glass successfully.
Research limitations/implications
The work is done in 2D, and it will not represent fully the 3D mechanisms.
Originality/value
Elastic and fracture behaviour of laminated glass under soft impact is simulated using the 2D FDEM. Limited work has been done on soft impact of laminated glass with FDEM, and special research endeavours are warranted. Benchmark examples and discussions are provided for future research.
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D.R.J. Owen, S.Y. Zhao and J.G. Loughran
A finite element solution to the rolling of two‐phase materials ispresented and applied to the rolling of prepared sugar cane. The generalizedBiot theory is extended and modified…
Abstract
A finite element solution to the rolling of two‐phase materials is presented and applied to the rolling of prepared sugar cane. The generalized Biot theory is extended and modified to suit the present problem and the velocity of the solid skeleton and the pore pressure are taken as the primary unknowns. The finite element approach is applied to the governing equations for spatial discretization, followed by time domain discretization by standard difference methods. A constitutive relation evaluated from a finite element simulation of experiments performed on a constrained compression test cell is employed. The computational model of the rolling of prepared cane with two rolls is presented. The material parameters of prepared cane are described and their variation during the rolling process are derived and discussed. Numerical results are presented to illustrate the performance and capability of the model and solution procedures.
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A. Gens and D.M. Potts
Elasto‐plastic models based on critical state formulations have been successful in describing many of the most important features of the mechanical behaviour of soils. This review…
Abstract
Elasto‐plastic models based on critical state formulations have been successful in describing many of the most important features of the mechanical behaviour of soils. This review paper deals with the applications of this class of models to the numerical analysis of geotechnical problems. After a brief overview of the development of the models, the basic critical state formulation is presented together with the main modifications which have actually been used in computational applications. The problems associated with the numerical implementation of this type of models are then discussed. Finally, a summary of reported computational applications and some specific examples of analyses of geotechnical problems using critical state models are presented.
L. JENDELE, A.H.C. CHAN and D.V. PHILLIPS
This paper deals with the well known degenerated shell element of Ahmad. The main concern focuses on the rank of the element stiffness matrix and the zero energy modes. Element…
Abstract
This paper deals with the well known degenerated shell element of Ahmad. The main concern focuses on the rank of the element stiffness matrix and the zero energy modes. Element formulation includes geometrical and material non‐linearities. The Lagrangian, heterosis and serendipity variants of displacement approximation are studied using full, selective or reduced in‐plane numerical integration. In the third direction the layered concept is adopted. The obtained results do not fully coincide with those published in References 2 and 3. The Figures presented in this paper, showing the displacement modes, clarify in a convenient form some of the element properties associated with particular element formulations. The work also shows the influence of the plastic and cracked material conditions on the stiffness matrix of the element.
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Alexandra C. H. Nowakowski, J. E. Sumerau and Lain A. B. Mathers
This chapter explores age-based variations in the healthcare experiences of transgender people. Specifically, we outline how transgender people narrate their experiences with…
Abstract
This chapter explores age-based variations in the healthcare experiences of transgender people. Specifically, we outline how transgender people narrate their experiences with coming out and transition in later life as well as possibilities for future research and clinical practice concerning older transgender populations. To this end, we begin with a review of the limited literature on older transgender populations including the ways such findings converge and diverge from studies of younger transgender populations. Then, we analyze data gathered from older transgender people throughout the United States concerning their experiences with health events, healthcare providers, and healthcare settings. For this empirical analysis, we draw on over 250 qualitative responses from transgender people over the age of 40. The findings of this chapter demonstrate the importance of adjusting existing healthcare protocols to provide adequate care for aging transgender populations. Specifically, our analyses highlight gaps in access and quality of healthcare delivery as well as issues related to medical education, trans-inclusive protocols, and sex-gender segregated medical traditions. The implications of our work here reveal important possibilities for expanding transgender healthcare access as well as existing barriers to such access. We specifically utilize the case of our respondents and the existing literature to illuminate gaps in needs assessment and healthcare delivery concerning older transgender populations. We will conclude the chapter with recommendations for bridging such gaps in research, education, and system operation.
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For those who are working with the finite element method, one may somehow wonder why a n point Gauss‐Legendre quadrature formula can integrate a 2n—1 order polynomial exactly. The…
Abstract
For those who are working with the finite element method, one may somehow wonder why a n point Gauss‐Legendre quadrature formula can integrate a 2n—1 order polynomial exactly. The purpose of this note is to unravel the secret.
Dilara Eylül Koç and Şevki Ulema
Tourist guides undertake many versatile roles as a requirement of their profession. The realisation of these roles also affects the performance of the guide. Findings obtained…
Abstract
Tourist guides undertake many versatile roles as a requirement of their profession. The realisation of these roles also affects the performance of the guide. Findings obtained from empirical evidence on the effects of the tour guide's performance on memorable tourism experiences and the intention to revisit the Cappadocia region shed light on the importance of these elements on each other. Accordingly, the primary purposes of this research are to measure the effect of tourist guides' performance on memorable tourism experiences and the impact of memorable tourism experiences on revisit intention (RVI). For these purposes, the survey technique obtained data from 569 domestic and foreign tourists who participated in guided tours in the Cappadocia region. According to the results of the research, it has been observed that the performance of the tourist guide influences the memorable tourism experience, and the memorable tourism experience affects RVI. In light of the results, suggestions to tourism stakeholders and researchers are listed.
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The Lanczos method with the Golub and Kahan bidiagonalization algorithm is used to solve non‐symmetric diagonal dominant simultaneous equations. The method is very suitable for…
Abstract
The Lanczos method with the Golub and Kahan bidiagonalization algorithm is used to solve non‐symmetric diagonal dominant simultaneous equations. The method is very suitable for sparse matrix and vector computer. The problem with loss of orthogonal property is dealt with by restating the iteration. Numerical examples together with FORTRAN 77 routine are given to illustrate the algorithm. Both scalar and vector CPU times are given for comparison.
A mesoscopic phase field (PF) model is proposed to simulate the meso-failure process of lightweight concrete.
Abstract
Purpose
A mesoscopic phase field (PF) model is proposed to simulate the meso-failure process of lightweight concrete.
Design/methodology/approach
The PF damage model is applied to the meso-failure process of lightweight concrete through the ABAQUS subroutine user-defined element (UEL). And the improved staggered iteration scheme with a one-pass procedure is used to alternately solve the coupling equations.
Findings
These examples clearly show that the crack initiation of the lightweight concrete specimens mainly occurs in the ceramsite aggregates with weak strength, especially in the larger aggregates. The crack propagation paths of the specimens with the same volume fraction of light aggregates are completely different, but the crack propagation paths all pass through the ceramsite aggregates near the cracks. The results also showed that with the increase in the volume fractions of the aggregates, the slope and the peak loads of the force-deflection (F-d) curves gradually decrease, the load-bearing capacity of the lightweight concrete specimens decreases, and crack branching and coalescence are less likely during crack propagation.
Originality/value
The mesostructures with a mortar matrix, aggregates and an interfacial transition zone (ITZ) are generated by an automatic generation and placement program, thus incorporating the typical three-phase characteristics of lightweight concrete into the PF model.
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