cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.14325209.v1
title: The Equivalent Linearization Method with a Weighted Averaging for Analyzing of Nonlinear Vibrating Systems

description: Abstract In this paper, the Equivalent Linearization Method (ELM) with a weighted averaging, which is proposed by Anh (Anh, 2015), is applied to analyze some vibrating systems with nonlinearities. The strongly nonlinear Duffing oscillator with third, fifth, and seventh powers of the amplitude, the other strongly nonlinear oscillators and the cubic Duffing with discontinuity are considered. The results obtained via this method are compared with the ones achieved by the Min-Max Approach (MMA), the Modified Lindstedt - Poincare Method (MLPM), the Parameter - Expansion Method (PEM), the Homotopy Perturbation Method (HPM) and 4th order Runge-Kutta method. The obtained results demonstrate that this method is very convenient for solving nonlinear equations and also can be successfully exerted to a lot of practical engineering and physical problems.
DOI: 10.6084/m9.figshare.5666974
title: Buckling of Slender Concrete-Filled Steel Tubes with Compliant Interfaces

description: Abstract This paper presents an exact model for studying the global buckling of concrete-filled steel tubular (CFST) columns with compliant interfaces between the concrete core and steel tube. This model is then used to evaluate exact critical buckling loads and modes of CFST columns. The results prove that interface compliance can considerably reduce the critical buckling loads of CFST columns. A good agreement between analytical and experimental buckling loads is obtained if at least one among longitudinal and radial interfacial stiffnesses is high. The parametric study reveals that buckling loads of CFST columns are very much affected by the interfacial stiffness and boundary conditions.
DOI: 10.6084/m9.figshare.5666974.v1
title: Buckling of Slender Concrete-Filled Steel Tubes with Compliant Interfaces

description: Abstract This paper presents an exact model for studying the global buckling of concrete-filled steel tubular (CFST) columns with compliant interfaces between the concrete core and steel tube. This model is then used to evaluate exact critical buckling loads and modes of CFST columns. The results prove that interface compliance can considerably reduce the critical buckling loads of CFST columns. A good agreement between analytical and experimental buckling loads is obtained if at least one among longitudinal and radial interfacial stiffnesses is high. The parametric study reveals that buckling loads of CFST columns are very much affected by the interfacial stiffness and boundary conditions.
DOI: 10.6084/m9.figshare.5667511
title: Application of Short Fibers Reinforced Composites in Power Transmission Coupling

description: Abstract In this study the use of short glass, carbon and hybrid glass-carbon fibers reinforced polymeric composites in power transmission coupling is investigated. The presented work is generalized to thermoplastic and thermoset polymeric matrix composites. The effects of the constituents weight percentages, and average fibers length on the composite tensile strength and modulus are studied using the Taguchi design of experiments method. A new approach of Finite Element analysis is introduced to model the effect of the hybrid fibers random distribution and average fibers length among the volume of the matrix. Each fiber is simulated independently in the model as a three dimensional truss element embedded in the matrix. The FEA model is applied on the tensile specimen and then on the power transmission coupling simulation. Finally, the new approach of finite element analysis results on the coupling are validated.
DOI: 10.6084/m9.figshare.5667511.v1
title: Application of Short Fibers Reinforced Composites in Power Transmission Coupling

description: Abstract In this study the use of short glass, carbon and hybrid glass-carbon fibers reinforced polymeric composites in power transmission coupling is investigated. The presented work is generalized to thermoplastic and thermoset polymeric matrix composites. The effects of the constituents weight percentages, and average fibers length on the composite tensile strength and modulus are studied using the Taguchi design of experiments method. A new approach of Finite Element analysis is introduced to model the effect of the hybrid fibers random distribution and average fibers length among the volume of the matrix. Each fiber is simulated independently in the model as a three dimensional truss element embedded in the matrix. The FEA model is applied on the tensile specimen and then on the power transmission coupling simulation. Finally, the new approach of finite element analysis results on the coupling are validated.
DOI: 10.6084/m9.figshare.5734425
title: A New Fifth-Order Shear and Normal Deformation Theory for Static Bending and Elastic Buckling of P-FGM Beams

description: Abstract A new fifth-order shear and normal deformation theory (FOSNDT) is developed for the static bending and elastic buckling analysis of functionally graded beams. The properties of functionally graded material are assumed to vary through the thickness direction according to power-law distribution (P-FGM). The most important feature of the present theory is that it includes the effects of transverse shear and normal deformations. Axial and transverse displacements involve polynomial shape functions to include the effects of transverse shear and normal deformations. A polynomial shape function expanded up to fifth-order in terms of the thickness coordinate is used to account for the effects of transverse shear and normal deformations. The kinematics of the present theory is based on six independent field variables. The theory satisfies the traction free boundary conditions at top and bottom surfaces of the beam without using problem dependent shear correction factor. The closed-form solutions of simply supported FG beams are obtained using Navier’s solution procedure and non-dimensional results are compared with those obtained by using classical beam theory, first order shear deformation theory and other higher order shear deformation theories. It is concluded that the present theory is accurate and efficient in predicting the bending and buckling responses of functionally graded beams.
DOI: 10.6084/m9.figshare.5734425.v1
title: A New Fifth-Order Shear and Normal Deformation Theory for Static Bending and Elastic Buckling of P-FGM Beams

description: Abstract A new fifth-order shear and normal deformation theory (FOSNDT) is developed for the static bending and elastic buckling analysis of functionally graded beams. The properties of functionally graded material are assumed to vary through the thickness direction according to power-law distribution (P-FGM). The most important feature of the present theory is that it includes the effects of transverse shear and normal deformations. Axial and transverse displacements involve polynomial shape functions to include the effects of transverse shear and normal deformations. A polynomial shape function expanded up to fifth-order in terms of the thickness coordinate is used to account for the effects of transverse shear and normal deformations. The kinematics of the present theory is based on six independent field variables. The theory satisfies the traction free boundary conditions at top and bottom surfaces of the beam without using problem dependent shear correction factor. The closed-form solutions of simply supported FG beams are obtained using Navier’s solution procedure and non-dimensional results are compared with those obtained by using classical beam theory, first order shear deformation theory and other higher order shear deformation theories. It is concluded that the present theory is accurate and efficient in predicting the bending and buckling responses of functionally graded beams.
DOI: 10.6084/m9.figshare.5861796
title: On a Four-Node Quadrilateral Plate for Laminated Composites

description: Abstract An assessment of the efficiency and convergence characteristics of a four-node quadrilateral plate finite element in the analysis of laminated composites is performed. The element, which is suitable for global response analysis, is developed in the framework of the strain gradient notation such that its modeling capabilities as well as modeling deficiencies can be physically interpreted by the analyst during the formulation process. Thus, shear locking typically encountered in four-noded plate elements is identified as caused by spurious terms which appear in the shear strain polynomial expansions. These identified spurious terms are removed a priori such that shear locking does not occur during numerical analysis and numerical remedies do not need to be applied. Stress solutions for different laminated plates are presented to demonstrate that the corrected model converges well to reference solutions.
DOI: 10.6084/m9.figshare.5861796.v1
title: On a Four-Node Quadrilateral Plate for Laminated Composites

description: Abstract An assessment of the efficiency and convergence characteristics of a four-node quadrilateral plate finite element in the analysis of laminated composites is performed. The element, which is suitable for global response analysis, is developed in the framework of the strain gradient notation such that its modeling capabilities as well as modeling deficiencies can be physically interpreted by the analyst during the formulation process. Thus, shear locking typically encountered in four-noded plate elements is identified as caused by spurious terms which appear in the shear strain polynomial expansions. These identified spurious terms are removed a priori such that shear locking does not occur during numerical analysis and numerical remedies do not need to be applied. Stress solutions for different laminated plates are presented to demonstrate that the corrected model converges well to reference solutions.
DOI: 10.6084/m9.figshare.6504431
title: Approximate solutions of large amplitude vibration of a string

description: Abstract In the present study, the response of a flexible string with large amplitude transverse vibration is studied utilizing amplitude-frequency formulation, improved amplitude-frequency formulation and max-min approach. In order to verify the accuracy of these approaches, obtained results are compared with other methods such as variational approach method, variational iteration method, coupling Newton’s method with the harmonic balance method and Hamiltonian approach. It has been found that for this problem, while amplitude-frequency formulation and max-min approach give the same results, improved amplitude frequency formulation is not an appropriate choice.
DOI: 10.6084/m9.figshare.6504431.v1
title: Approximate solutions of large amplitude vibration of a string

description: Abstract In the present study, the response of a flexible string with large amplitude transverse vibration is studied utilizing amplitude-frequency formulation, improved amplitude-frequency formulation and max-min approach. In order to verify the accuracy of these approaches, obtained results are compared with other methods such as variational approach method, variational iteration method, coupling Newton’s method with the harmonic balance method and Hamiltonian approach. It has been found that for this problem, while amplitude-frequency formulation and max-min approach give the same results, improved amplitude frequency formulation is not an appropriate choice.
DOI: 10.6084/m9.figshare.5931256
title: A Simple FEM Formulation Applied to Nonlinear Problems of Impact with Thermomechanical Coupling

description: Abstract The thermal effects of problems involving deformable structures are essential to describe the behavior of materials in feasible terms. Verifying the transformation of mechanical energy into heat it is possible to predict the modifications of mechanical properties of materials due to its temperature changes. The current paper presents the numerical development of a finite element method suitable for nonlinear structures coupled with thermomechanical behavior; including impact problems. A simple and effective alternative formulation is presented, called FEM positional, to deal with the dynamic nonlinear systems. The developed numerical is based on the minimum potential energy written in terms of nodal positions instead of displacements. The effects of geometrical, material and thermal nonlinearities are considered. The thermodynamically consistent formulation is based on the laws of thermodynamics and the Helmholtz free-energy, used to describe the thermoelastic and the thermoplastic behaviors. The coupled thermomechanical model can result in secondary effects that cause redistributions of internal efforts, depending on the history of deformation and material properties. The numerical results of the proposed formulation are compared with examples found in the literature.
DOI: 10.6084/m9.figshare.5931256.v1
title: A Simple FEM Formulation Applied to Nonlinear Problems of Impact with Thermomechanical Coupling

description: Abstract The thermal effects of problems involving deformable structures are essential to describe the behavior of materials in feasible terms. Verifying the transformation of mechanical energy into heat it is possible to predict the modifications of mechanical properties of materials due to its temperature changes. The current paper presents the numerical development of a finite element method suitable for nonlinear structures coupled with thermomechanical behavior; including impact problems. A simple and effective alternative formulation is presented, called FEM positional, to deal with the dynamic nonlinear systems. The developed numerical is based on the minimum potential energy written in terms of nodal positions instead of displacements. The effects of geometrical, material and thermal nonlinearities are considered. The thermodynamically consistent formulation is based on the laws of thermodynamics and the Helmholtz free-energy, used to describe the thermoelastic and the thermoplastic behaviors. The coupled thermomechanical model can result in secondary effects that cause redistributions of internal efforts, depending on the history of deformation and material properties. The numerical results of the proposed formulation are compared with examples found in the literature.
DOI: 10.6084/m9.figshare.6504437.v1
title: Strength analysis of composite cables

description: Abstract Carbon Fiber Reinforced Polymer (CFRP) cables, due to their outstanding performance in terms of specific stiffness and strength, are usually found in civil construction applications and, more recently, in the Oil & Gas sector. However, experimental data and theoretical solutions for these cables are very limited. On the contrary, several theoretical and numerical approaches are available for isotropic cables (metallic wire ropes), some of them with severe simplifications, nonetheless showing good agreement with experimental data. In this study, experimental tensile results for 1×7 CRFP cables were compared to a simplified analytical model (assumed transversally isotropic) and to a 3D finite element model incorporating the experimental uncertainty in important input parameters: longitudinal elastic modulus, Poisson’s ratio, static friction coefficient and ultimate tensile strain. The average experimental breaking load of the cable was 190.25 kN (coefficient of variation of 1.74%) and the agreement with the numerical model predictions were good, with an average-value deviation of –1.15%, which is lower than the experimental variations. The simplified analytical model yielded a discrepancy above 10%, indicating that it needs further refinement although much less time consuming than the numerical model. These conclusions were corroborated by statistical analyses (i.e. Kruskal–Wallis and Mann-Whitney).
DOI: 10.6084/m9.figshare.6504437
title: Strength analysis of composite cables

description: Abstract Carbon Fiber Reinforced Polymer (CFRP) cables, due to their outstanding performance in terms of specific stiffness and strength, are usually found in civil construction applications and, more recently, in the Oil & Gas sector. However, experimental data and theoretical solutions for these cables are very limited. On the contrary, several theoretical and numerical approaches are available for isotropic cables (metallic wire ropes), some of them with severe simplifications, nonetheless showing good agreement with experimental data. In this study, experimental tensile results for 1×7 CRFP cables were compared to a simplified analytical model (assumed transversally isotropic) and to a 3D finite element model incorporating the experimental uncertainty in important input parameters: longitudinal elastic modulus, Poisson’s ratio, static friction coefficient and ultimate tensile strain. The average experimental breaking load of the cable was 190.25 kN (coefficient of variation of 1.74%) and the agreement with the numerical model predictions were good, with an average-value deviation of –1.15%, which is lower than the experimental variations. The simplified analytical model yielded a discrepancy above 10%, indicating that it needs further refinement although much less time consuming than the numerical model. These conclusions were corroborated by statistical analyses (i.e. Kruskal–Wallis and Mann-Whitney).
DOI: 10.6084/m9.figshare.6504443
title: Numerical Study On Multi Layered Target Material Subjected To Impact Loading

description: Abstract In this study, the glass/epoxy composite laminate is layered with polyurethane foam/ polyurethane sheet and silicon carbide to analyse their response during high mass and low velocity impact. The silicon carbide is layered in two forms, one is as plate and the other is as inserts. The target materials are prepared in various combinations and the bonding of layers is done by using epoxy. Effectiveness of silicon carbide inserts and plates are compared in terms of their energy absorbing capacities. The numerical simulation is also carried for the target material with the same experimental conditions. The experimental results are compared with the numerical results for validation and a reasonably good agreement is found. Further, the validated numerical model is extended to understand the ballistic performance of the target material. It is observed that the introduction of silicon carbide as front layer improves both the structural and ballistic performance. Also, the damage in case of samples with silicon carbide inserts is localized as opposed to that of silicon carbide plate.
DOI: 10.6084/m9.figshare.6504443.v1
title: Numerical Study On Multi Layered Target Material Subjected To Impact Loading

description: Abstract In this study, the glass/epoxy composite laminate is layered with polyurethane foam/ polyurethane sheet and silicon carbide to analyse their response during high mass and low velocity impact. The silicon carbide is layered in two forms, one is as plate and the other is as inserts. The target materials are prepared in various combinations and the bonding of layers is done by using epoxy. Effectiveness of silicon carbide inserts and plates are compared in terms of their energy absorbing capacities. The numerical simulation is also carried for the target material with the same experimental conditions. The experimental results are compared with the numerical results for validation and a reasonably good agreement is found. Further, the validated numerical model is extended to understand the ballistic performance of the target material. It is observed that the introduction of silicon carbide as front layer improves both the structural and ballistic performance. Also, the damage in case of samples with silicon carbide inserts is localized as opposed to that of silicon carbide plate.
DOI: 10.6084/m9.figshare.6504428
title: A Parametric Study on the Centrifugal Force-Induced Stress and Displacements in Power-Law Graded Hyperbolic Discs

description: Abstract An extensive parametric study on the variation of the centrifugal-force-induced stress and displacements with the inhomogeneity indexes, profile parameters and boundary conditions is conducted based on the author’s recently published analytical formulas for radially functionally power-law graded rotating hyperbolic discs under axisymmetric conditions. The radial variation of the thickness of the disc is chosen to obey a hyperbolic function defined either convergent or divergent. In the present work, contrary to the published one, it is assumed that both Young’s modulus and density radially vary with the same inhomogeneity index to enable to conduct a parametric study. Under this additional assumption, for the values of the chosen power-law indexes β = − 5, 0, 5 for the material grading rule, and the chosen profile parameters m = − 1, − 0.75, − 0.5, − 0.25, 0, 0.25, 0.5, 0.75, 1 for a hyperbolic disc; the variations of the radial stress, the hoop stress and the radial displacement are all illustrated graphically for a rotating disc whose both surfaces are stress-free, for a rotating disc mounted a rigid shaft at its center and its outer surface is stress-free, and finally for a rotating disc attached a rigid shaft at its center and guided at its outer surface (a rigid casing exists at the outer surface).
DOI: 10.6084/m9.figshare.6504428.v1
title: A Parametric Study on the Centrifugal Force-Induced Stress and Displacements in Power-Law Graded Hyperbolic Discs

description: Abstract An extensive parametric study on the variation of the centrifugal-force-induced stress and displacements with the inhomogeneity indexes, profile parameters and boundary conditions is conducted based on the author’s recently published analytical formulas for radially functionally power-law graded rotating hyperbolic discs under axisymmetric conditions. The radial variation of the thickness of the disc is chosen to obey a hyperbolic function defined either convergent or divergent. In the present work, contrary to the published one, it is assumed that both Young’s modulus and density radially vary with the same inhomogeneity index to enable to conduct a parametric study. Under this additional assumption, for the values of the chosen power-law indexes β = − 5, 0, 5 for the material grading rule, and the chosen profile parameters m = − 1, − 0.75, − 0.5, − 0.25, 0, 0.25, 0.5, 0.75, 1 for a hyperbolic disc; the variations of the radial stress, the hoop stress and the radial displacement are all illustrated graphically for a rotating disc whose both surfaces are stress-free, for a rotating disc mounted a rigid shaft at its center and its outer surface is stress-free, and finally for a rotating disc attached a rigid shaft at its center and guided at its outer surface (a rigid casing exists at the outer surface).
DOI: 10.6084/m9.figshare.6504758
title: Energy based collocation method to predict progressive damage behavior of imperfect composite plates under compression

description: Abstract A new collocation methodology is presented to predict failure and progressive damage behavior of composite plates in this paper. The present work deals with composite plates containing initial geometric imperfections and different boundary conditions under uniaxial in-plane compressive load. In the present study, the domain is discretized with Legendre-Gauss-Lobatto nodes and the approximation of displacement fields is performed by Legendre Basis Functions (LBFs). The onset of damage and damage evolution are predicted by Hashin’s failure criteria and by proposed material degradation models. Three geometric degradation models are also assumed to estimate the degradation zone around the failure location which are named complete, region and node degradation models.