cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.14325327
title: Development of train ride comfort prediction model for railway slab track system

description: Abstract Despite considerable importance of train ride comfort (TRC) in railway slab tracks, there is no TRC prediction model for the slab tracks in the available literature. In this regard, a practical TRC prediction model was developed in this research, taking into account all the track and rolling stock influencing parameters. For this purpose, a vehicle/slab-track interaction model was developed. The model was validated using the results obtained from a comprehensive field test. The effects of rail pad, resilient layer, subgrade, properties of rolling stock suspension systems and vehicle speed on the TRC were studied through a parametric study of the model in which random rail irregularities with various severities were considered. The results obtained were used to develop the TRC prediction model. The accuracy of the model predictions was evaluated by comparing them with those obtained from a railway field. It was shown that the TRC prediction model developed here is a reliable tool for estimation of the TRC from slab track properties, rolling stock parameters and track irregularities. Applicability of the model in the real world of practice is illustrated.
DOI: 10.6084/m9.figshare.14325306.v1
title: Finite Elements for the One Variable Version of Mindlin-Reissner Plate

description: Abstract To analyze thin and thick plates, the paper presents two rectangular finite elements with high accuracy. In these elements, the proposed formulations of the displacement field utilize the Bergan-Wang approach, which depends only on one variable: the plate lateral deflection. This approach ensures that shear-locking problem will not happen as thickness decreases. The degrees of freedom of the proposed elements are twenty-four for the first element and it is named BWRE24, while the second one has thirty-six degrees of freedom and is named BWRE36. To evidence the efficiency of the two elements, a series of numerical examples for an isotropic plate subjected to various loadings and with different boundary conditions have been analyzed. Very good results are obtained suffering no numerical difficulties in case of very thin plates.
DOI: 10.6084/m9.figshare.14325327.v1
title: Development of train ride comfort prediction model for railway slab track system

description: Abstract Despite considerable importance of train ride comfort (TRC) in railway slab tracks, there is no TRC prediction model for the slab tracks in the available literature. In this regard, a practical TRC prediction model was developed in this research, taking into account all the track and rolling stock influencing parameters. For this purpose, a vehicle/slab-track interaction model was developed. The model was validated using the results obtained from a comprehensive field test. The effects of rail pad, resilient layer, subgrade, properties of rolling stock suspension systems and vehicle speed on the TRC were studied through a parametric study of the model in which random rail irregularities with various severities were considered. The results obtained were used to develop the TRC prediction model. The accuracy of the model predictions was evaluated by comparing them with those obtained from a railway field. It was shown that the TRC prediction model developed here is a reliable tool for estimation of the TRC from slab track properties, rolling stock parameters and track irregularities. Applicability of the model in the real world of practice is illustrated.
DOI: 10.6084/m9.figshare.14325330
title: On the sparsity of linear systems of equations for a new stress basis applied to three-dimensional Hybrid-Trefftz stress finite elements

description: Abstract Hybrid-Trefftz finite elements have been applied to the analysis of several types of structures successfully. It is based on two different sets of approximations applied simultaneously: stresses in the domain and displacements on its boundary. This method presents very large linear systems of equations to be solved. To overcome this issue, most authors have been careful in the choice of the approximation fields in order to have highly sparse linear systems. The natural choice for the stress basis has been linearly independent, hierarchical and orthogonal polynomials which typically result in more than 90% of sparsity in 3-D finite elements. Functions derived from associated Legendre and Chebyshev orthogonal polynomials have been used with success for this purpose. In this work the non-orthogonal polynomials available in the Pascal pyramid are proposed to derive a harmonic and complete set of polynomial basis as an alternative to the above-cited functions. Numerical tests show this basis produces accurate results. No significant differences were found when comparing the sparsity of the linear system of equations for both functions.
DOI: 10.6084/m9.figshare.14325330.v1
title: On the sparsity of linear systems of equations for a new stress basis applied to three-dimensional Hybrid-Trefftz stress finite elements

description: Abstract Hybrid-Trefftz finite elements have been applied to the analysis of several types of structures successfully. It is based on two different sets of approximations applied simultaneously: stresses in the domain and displacements on its boundary. This method presents very large linear systems of equations to be solved. To overcome this issue, most authors have been careful in the choice of the approximation fields in order to have highly sparse linear systems. The natural choice for the stress basis has been linearly independent, hierarchical and orthogonal polynomials which typically result in more than 90% of sparsity in 3-D finite elements. Functions derived from associated Legendre and Chebyshev orthogonal polynomials have been used with success for this purpose. In this work the non-orthogonal polynomials available in the Pascal pyramid are proposed to derive a harmonic and complete set of polynomial basis as an alternative to the above-cited functions. Numerical tests show this basis produces accurate results. No significant differences were found when comparing the sparsity of the linear system of equations for both functions.
DOI: 10.6084/m9.figshare.14325331
title: Perturbation based stochastic isogeometric analysis for bending of functionally graded plates with the randomness of elastic modulus

description: Abstract We propose, in this paper, stochastic isogeometric analysis (SIGA) is a type of non-statistic approach in which combines the perturbation technique with the standard isogeometric analysis, in particular for static behavior of functionally graded plates with the uncertain elastic modulus. We assume that the spatial random variation of elastic modulus can be modeled as a two dimensional Gaussian random field in the plane of the plate. The random field is discretized to set of random variables using the integration point method. The system equations of SIGA are created using the NURBS functions for approximation displacement fields in conjunction with the first-order and second-order perturbation expansions of random fields, stiffness matrix, displacement fields. Besides the non-statistic approach, Monte Carlo simulation is presented for validation. The accuracy and appropriateness of the non-statistic approach are demonstrated via comparisons of the present results with those given by the stochastic finite element method in the literature and by the Monte Carlo analysis as well. The numerical examples are employed to investigate the effect of the randomness of elastic modulus and system parameters on the first and second statistical moments of displacement.
DOI: 10.6084/m9.figshare.14325331.v1
title: Perturbation based stochastic isogeometric analysis for bending of functionally graded plates with the randomness of elastic modulus

description: Abstract We propose, in this paper, stochastic isogeometric analysis (SIGA) is a type of non-statistic approach in which combines the perturbation technique with the standard isogeometric analysis, in particular for static behavior of functionally graded plates with the uncertain elastic modulus. We assume that the spatial random variation of elastic modulus can be modeled as a two dimensional Gaussian random field in the plane of the plate. The random field is discretized to set of random variables using the integration point method. The system equations of SIGA are created using the NURBS functions for approximation displacement fields in conjunction with the first-order and second-order perturbation expansions of random fields, stiffness matrix, displacement fields. Besides the non-statistic approach, Monte Carlo simulation is presented for validation. The accuracy and appropriateness of the non-statistic approach are demonstrated via comparisons of the present results with those given by the stochastic finite element method in the literature and by the Monte Carlo analysis as well. The numerical examples are employed to investigate the effect of the randomness of elastic modulus and system parameters on the first and second statistical moments of displacement.
DOI: 10.6084/m9.figshare.14325337
title: Global/Local Non-Intrusive Crack Analysis Using Element Free Galerkin and Linear Galerkin Finite Volume Methods

description: Abstract Although various numerical methods are proposed to solve a wide range of problems so far, each has its own advantages and disadvantages. Therefore, it would be highly desirable to develop a computationally efficient combined approach, which makes use of their advantages and reduces their drawbacks. In this regard, a non-intrusive iterative global/local (IGL) algorithm is proposed to evaluate the structures with local discontinuity. Firstly, in each iteration, the entire continuum domain is solved using the Galerkin Finite Volume (GFV) method, which consumes light computational workload for predicting accurate results of linear structural response. Then, the Element Free Galerkin (EFG) meshless method is locally employed as an accurate but computationally expensive solver to cover the shortcomings of the GFV solver in the crack analysis. The specific form of Quasi-Newtonian and dynamic accelerators are adopted to increase the convergence rate in each computational increment. Finally, the proposed method's accuracy and speed are examined by computing stress intensity factors (SIFs) for several distinct 2D cracked models.
DOI: 10.6084/m9.figshare.14325339.v1
title: Bending Analysis of Functionally Graded Axisymmetric Circular Plates using the Dual Mesh Finite Domain Method

description: Abstract The dual mesh finite domain method (DMFDM) introduced by Reddy employs one mesh for the approximation of the primary variables (primal mesh) and another mesh for the satisfaction of the governing equations (dual mesh). The present study deals with the extension and application of the DMFDM to functionally graded circular plates under axisymmetric conditions. The formulation makes use of the traditional finite element interpolation of the primary variables with a primal mesh and a dual mesh to satisfy the integral form of the governing differential equations, the basic premise of the finite volume method. The method is used to analyze axisymmetric bending of through-thickness functionally graded circular plates using the classical plate theory (CPT) and first-order shear deformation plate theory (FST). The displacement model of the FST and the mixed model of the CPT using the DMFDM are developed along with the displacement and mixed finite element models. Numerical results are presented to illustrate the methodology and a comparison of the generalized displacements and bending moments computed with those of the corresponding finite element models. The influence of the extensional-bending coupling stiffness (due to the through-thickness grading of the material) on the deflections is also brought out.
DOI: 10.6084/m9.figshare.14325339
title: Bending Analysis of Functionally Graded Axisymmetric Circular Plates using the Dual Mesh Finite Domain Method

description: Abstract The dual mesh finite domain method (DMFDM) introduced by Reddy employs one mesh for the approximation of the primary variables (primal mesh) and another mesh for the satisfaction of the governing equations (dual mesh). The present study deals with the extension and application of the DMFDM to functionally graded circular plates under axisymmetric conditions. The formulation makes use of the traditional finite element interpolation of the primary variables with a primal mesh and a dual mesh to satisfy the integral form of the governing differential equations, the basic premise of the finite volume method. The method is used to analyze axisymmetric bending of through-thickness functionally graded circular plates using the classical plate theory (CPT) and first-order shear deformation plate theory (FST). The displacement model of the FST and the mixed model of the CPT using the DMFDM are developed along with the displacement and mixed finite element models. Numerical results are presented to illustrate the methodology and a comparison of the generalized displacements and bending moments computed with those of the corresponding finite element models. The influence of the extensional-bending coupling stiffness (due to the through-thickness grading of the material) on the deflections is also brought out.
DOI: 10.6084/m9.figshare.14325340
title: Open-Hole Kenaf Fiber Composites Under Elevated Temperatures: Experimental And Numerical Approaches

description: Abstract An experimental programme to investigate the notched strength of open-hole woven fabric kenaf fiber-reinforced polymer (WKRP) composite plates under quasi-static tensile loading. It was found that all testing coupons were failed in net-section, fracture initiated at the hole edge due to stress concentrations and propagated to the plate edge. A two-dimensional numerical modelling framework was developed following previously experimental series. A constitutive model of the traction-separation relationship was incorporated by using extended finite element model (XFEM) and cohesive zone model (CZM). Moreover, the effects of elevated temperatures and thermal expansion coefficient was incorporated within the modelling framework. Both modelling techniques were evaluated and compared, albeit to insignificant differences of maximum load output in both techniques, XFEM does not require apriori failure path compared to CZM. Good agreements between the predicted modelling work and measured notched strength were obtained, with discrepancies in the range of 0.4 - 25%, both displayed consistency in the net-section failures.
DOI: 10.6084/m9.figshare.14325340.v1
title: Open-Hole Kenaf Fiber Composites Under Elevated Temperatures: Experimental And Numerical Approaches

description: Abstract An experimental programme to investigate the notched strength of open-hole woven fabric kenaf fiber-reinforced polymer (WKRP) composite plates under quasi-static tensile loading. It was found that all testing coupons were failed in net-section, fracture initiated at the hole edge due to stress concentrations and propagated to the plate edge. A two-dimensional numerical modelling framework was developed following previously experimental series. A constitutive model of the traction-separation relationship was incorporated by using extended finite element model (XFEM) and cohesive zone model (CZM). Moreover, the effects of elevated temperatures and thermal expansion coefficient was incorporated within the modelling framework. Both modelling techniques were evaluated and compared, albeit to insignificant differences of maximum load output in both techniques, XFEM does not require apriori failure path compared to CZM. Good agreements between the predicted modelling work and measured notched strength were obtained, with discrepancies in the range of 0.4 - 25%, both displayed consistency in the net-section failures.
DOI: 10.6084/m9.figshare.14325343
title: Extracting the Solution of Three-Dimensional Wave Diffraction Problem from Two-Dimensional Analysis by Introducing an Artificial Neural Network for Floating Objects

description: Abstract The diffraction of the waves from the two ends of floating breakwaters (FBWs) that have limited length, are practically a three-dimensional (3D). In order to perform a two-dimensional vertical (2DV) analysis to solve the wave diffraction problem, some “correcting factors” are required to modify the 2DV results and make them comparable and verifiable against 3D solutions. The main objective of the current study is to propose a method to obtain these correcting factors and demonstrate its usefulness through some example cases. An Artificial Neural Network (ANN) is trained by three main non-dimensional independent variables to predict the mentioned factors. In order to set up the ANN, a database including both 2DV and 3D results is required. The 2DV results are obtained by employing a semi-analytical method, namely the Scaled Boundary Finite Element Method (SBFEM). A basic change in the location of the scaling center is implemented. The 3D results are obtained via ANSYS AQWA software. Eighty-one cases are simulated on a floating object with rectangular cross-sections. The correlation factor R = 0.9607 for a group of new samples shows that the predicted results are closely matched to the target values. The correcting factor applies the 3D effects of diffracted waves around the structures on 2DV results and produces a more accurate prediction.
DOI: 10.6084/m9.figshare.14325343.v1
title: Extracting the Solution of Three-Dimensional Wave Diffraction Problem from Two-Dimensional Analysis by Introducing an Artificial Neural Network for Floating Objects

description: Abstract The diffraction of the waves from the two ends of floating breakwaters (FBWs) that have limited length, are practically a three-dimensional (3D). In order to perform a two-dimensional vertical (2DV) analysis to solve the wave diffraction problem, some “correcting factors” are required to modify the 2DV results and make them comparable and verifiable against 3D solutions. The main objective of the current study is to propose a method to obtain these correcting factors and demonstrate its usefulness through some example cases. An Artificial Neural Network (ANN) is trained by three main non-dimensional independent variables to predict the mentioned factors. In order to set up the ANN, a database including both 2DV and 3D results is required. The 2DV results are obtained by employing a semi-analytical method, namely the Scaled Boundary Finite Element Method (SBFEM). A basic change in the location of the scaling center is implemented. The 3D results are obtained via ANSYS AQWA software. Eighty-one cases are simulated on a floating object with rectangular cross-sections. The correlation factor R = 0.9607 for a group of new samples shows that the predicted results are closely matched to the target values. The correcting factor applies the 3D effects of diffracted waves around the structures on 2DV results and produces a more accurate prediction.
DOI: 10.6084/m9.figshare.14325345.v1
title: A Locally-Continuous Meshless Local Petrov-Galerkin Method Applied to a Two-point Boundary Value Problem

description: Abstract In recent years, the Meshless Local Petrov-Galerkin (MLPG) Method has attracted the attention of many researchers in solving several types of boundary value problems. This method is based on a local weak form, evaluated in local subdomains and does not require any mesh, either in the construction of the test and shape functions or in the integration process. However, the shape functions used in MLPG have complicated forms, which makes their computation and their derivative's computation costly. In this work, using the Moving Least Square (MLS) Method, we dissociate the point where the approximating polynomial's coefficients are optimized, from the points where its derivatives are computed. We argue that this approach not only is consistent with the underlying approximation hypothesis, but also makes computation of derivatives simpler. We apply our approach to a two-point boundary value problem and perform several tests to support our claim. The results show that the proposed model is efficient, achieves good precision, and is attractive to be applied to other higher-dimension problems.
DOI: 10.6084/m9.figshare.14325345
title: A Locally-Continuous Meshless Local Petrov-Galerkin Method Applied to a Two-point Boundary Value Problem

description: Abstract In recent years, the Meshless Local Petrov-Galerkin (MLPG) Method has attracted the attention of many researchers in solving several types of boundary value problems. This method is based on a local weak form, evaluated in local subdomains and does not require any mesh, either in the construction of the test and shape functions or in the integration process. However, the shape functions used in MLPG have complicated forms, which makes their computation and their derivative's computation costly. In this work, using the Moving Least Square (MLS) Method, we dissociate the point where the approximating polynomial's coefficients are optimized, from the points where its derivatives are computed. We argue that this approach not only is consistent with the underlying approximation hypothesis, but also makes computation of derivatives simpler. We apply our approach to a two-point boundary value problem and perform several tests to support our claim. The results show that the proposed model is efficient, achieves good precision, and is attractive to be applied to other higher-dimension problems.
DOI: 10.6084/m9.figshare.14325348.v1
title: An Overview of Buckling and Imperfection of Cone-Cylinder Transition under Various Loading Condition

description: Abstract The current paper presents a brief survey of literature relevant to buckling of cone-cylinder intersection under different loads such as (i) internal pressure, (ii) external pressure, and (iii) axial compression. The paper explores the up-to-date knowledge on the buckling of cone-cylinder intersection and highlights the areas of gap in knowledge. This is aimed at contributing to better understanding of the relevant issues such as the influence of different types of imperfections in updating the current design guideline that is found to be vital in industrial practice. The review is thematically divided into: (i) the methods adopted in the past work (i.e., how the data were obtained, type of material used, type of design with/without reinforcement), (ii) the highlight and importance of past findings, (iii) the sensitivity to imperfection and its design implications and (iv) the current design recommendation and guidelines. Finally, the current paper provides a brief state-of-the-art and presents an update of related works for the future establishment of shells design guidelines.
DOI: 10.6084/m9.figshare.14325348
title: An Overview of Buckling and Imperfection of Cone-Cylinder Transition under Various Loading Condition

description: Abstract The current paper presents a brief survey of literature relevant to buckling of cone-cylinder intersection under different loads such as (i) internal pressure, (ii) external pressure, and (iii) axial compression. The paper explores the up-to-date knowledge on the buckling of cone-cylinder intersection and highlights the areas of gap in knowledge. This is aimed at contributing to better understanding of the relevant issues such as the influence of different types of imperfections in updating the current design guideline that is found to be vital in industrial practice. The review is thematically divided into: (i) the methods adopted in the past work (i.e., how the data were obtained, type of material used, type of design with/without reinforcement), (ii) the highlight and importance of past findings, (iii) the sensitivity to imperfection and its design implications and (iv) the current design recommendation and guidelines. Finally, the current paper provides a brief state-of-the-art and presents an update of related works for the future establishment of shells design guidelines.