Tarun Kant - Academia.edu (original) (raw)
Papers by Tarun Kant
Journal of Sandwich Structures & Materials, 2005
Two higher-order shear deformable finite element models using a higher-order facet shell element ... more Two higher-order shear deformable finite element models using a higher-order facet shell element are presented for the free vibration analysis of layered anisotropic sandwich laminates. One of the higher-order shear deformation models accounts for the effects of both transverse shear strains/stresses and the transverse normal strain/stress, while the other includes only the effects of the transverse shear deformation. The accuracy of the present models is demonstrated by comparing the results of laminated sandwich plates with the available closed- form solutions. Benchmark solutions with the parametric study for the laminated sandwich cylindrical and spherical shell panels are also presented.
Journal of Applied Mechanics, 1990
International Journal for Computational Methods in Engineering Science and Mechanics, 2007
A simple, semi-analytical methodology defining a two-point boundary value problem (BVP) governed ... more A simple, semi-analytical methodology defining a two-point boundary value problem (BVP) governed by a set of linear first-order ordinary differential equations (ODEs) with mixed primary variables whose number equals the order of partial differential equations (PDEs) for narrow layered ...
Communications in Numerical Methods in Engineering, 2006
COMMUNICATIONS IN NUMERICAL METHODS IN ENGINEERING Commun. Numer. Meth. Engng 2008; 24:1532 Publ... more COMMUNICATIONS IN NUMERICAL METHODS IN ENGINEERING Commun. Numer. Meth. Engng 2008; 24:1532 Published online 7 November 2006 in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/cnm.952 ... Stress analyses of laminates ...
Composites Science and Technology, 1988
Advances in Structural Engineering, 2014
ABSTRACT Functionally graded materials (FGMs) are recently developed advanced composite materials... more ABSTRACT Functionally graded materials (FGMs) are recently developed advanced composite materials and are being widely used in various innovative engineering appliances. In recent years FGMs are gaining considerable importance and finding wide applications in high temperature environments, such as, fusion-based nuclear reactors, chemical plants, aerospace structural applications, etc. A mixture of ceramic and metal or, a combination of different materials is used to make FGMs. New methodologies need to be developed for engineering characterization of FGMs with their increase in applications in various fields, and also to analyse and design structural components, viz., beams, plates and shells made of these advanced materials with reasonably high accuracy and computational efforts. In view of above, an accurate higher order shear and normal deformation plate theory is employed for stress and free vibration analyses of functionally graded (FG) elastic, rectangular, and simply supported (diaphragm) plates in the present study. The theoretical model is based on Taylor's series expansion of in-plane and transverse displacements in thickness coordinate defining the plate deformations. FGMs are idealized as continua with mechanical properties changing smoothly with respect to spatial coordinates. The material properties of FG plates are assumed to be varying through thickness of plate in a continuous manner. Poisson’s ratios of FG plates are assumed constant, but their Young’s modulii and densities vary continuously in thickness direction according to the volume fraction of constituents which is modelled here as exponential and power law functions. The effect of variation of material properties in terms of its gradation index on deformations, stresses and natural frequency of FG plates are studied.
IUTAM Symposium on Multi-Functional Material Structures and Systems, 2009
Abstract Estimation of displacements and stresses in functionally graded (FG) beams and plates ar... more Abstract Estimation of displacements and stresses in functionally graded (FG) beams and plates are carried out using higher order shear and normal deformation theories (HOSNTs). Taylor's series expansion is adopted to approximate primary displacements in the thickness ...
Journal of Sound and Vibration, 2011
Journal of Engineering Mechanics, 2011
International Journal of Pressure Vessels and Piping, 1974
for a number of cases and for a given set of values of elastic moduli, Poisson's ratio and thickn... more for a number of cases and for a given set of values of elastic moduli, Poisson's ratio and thickness/diameter ratio. The results are compared with the known results available in literature and also with the stresses predicted by the .4SME Code.
International Journal of Pressure Vessels and Piping, 2004
The performance of the Chaboche kinematic hardening model has been evaluated in this paper to pre... more The performance of the Chaboche kinematic hardening model has been evaluated in this paper to predict the ratchetting responses for a broad set of uniaxial and biaxial loading histories. The investigations have been performed with reference to both uniaxial and biaxial experimental data, viz. (a) strain and stress controlled uniaxial tests on tensile specimens; (b) biaxial tests on straight pipes with constant internal pressure and cyclic bending load; and (c) a shake table test on elbow. The parameters of the Chaboche model have been calculated from the uniaxial strain controlled stable hysteresis loop. Amongst the various parameters in the Chaboche model, it has been found that the selection of the value of g 3 plays a crucial role in achieving better simulation. The Chaboche model was observed to predict complete shakedown for g 3 ¼ 0: On the other hand, the model closely simulated the experimental results for g 3 ¼ 9: The same parameters have been used to analyze the biaxial loading condition. Ratchetting simulation studies by the Chaboche model have resulted in reasonably good agreement with experiments.
International Journal of Pressure Vessels and Piping, 2003
The phenomenon of ratchetting is defined as constant accumulation of plastic strain or deformatio... more The phenomenon of ratchetting is defined as constant accumulation of plastic strain or deformation under combined steady state and cyclic loading. It can reduce the fatigue life or can cause failure of piping components or systems subjected to seismic or other cyclic loads. The uniaxial ratchetting characteristics of SA333 Gr.6 steel have been investigated at room temperature in the present paper. The specimens were subjected to cyclic axial stress with a constant mean stress of 200 MPa and a varying amplitude stress of 149, 174, 199 and 224 MPa. Tests were also performed on 203.2 mm, Sch 80, SA333 Gr. 6 carbon steel straight pipe. The pipe was subjected to a constant internal pressure of 18 MPa and a cyclic bending load. The effects of amplitude of load on the rate of ratchetting have also been investigated in the present paper. The uniaxial experiments showed that specimens exhibited shakedown at low stress amplitude after some strain accumulation. However, specimens experienced continuous ratchetting at higher stress amplitudes with no shakedown before failure. Ovalization of the pipe crosssection was observed when the pipe was subjected to constant internal pressure and cyclic point load. Local bulging was observed at higher loading. The pipe did not show any shakedown behaviour for the given cycles of loading and exhibited continuous ratchetting under the varying amplitude loading.
Engineering Computations, 1988
A C° finite element formulation for flexure‐membrane coupling behaviour of an unsymmetrically lam... more A C° finite element formulation for flexure‐membrane coupling behaviour of an unsymmetrically laminated plate based on a higher‐order displacement model and three‐dimensional state of stress and strain is presented. This theory incorporates the more realistic non‐linear variation of displacements through the plate thickness, thus eliminating the use of a shear correction coefficient. The discrete element chosen is a nine‐noded quadrilateral with 12 degrees of freedom per node. The computer program developed incorporates the realistic prediction of interlaminar stresses from equilibrium equations. The present solution for deflection and stresses is compared with those obtained using three‐dimensional elasticity theory, another higher‐order shear deformation theory and Mindlin theory. In addition, numerical results for unsymmetric sandwich plates are presented for future reference.
Computers & Structures, 1994
Ahatraet-The well-known central difference predictor method used for the analysis of nonlinear sy... more Ahatraet-The well-known central difference predictor method used for the analysis of nonlinear systems, subjected to transient dynamic loads, is modified by incorporating Rayleigh's damping into the governing incremental equation of motion. The new time-stepping scheme requires a starting algorithm for both the first and second time-steps, and can effectively be used to analyse the nonlinear damped systems in general.
Computers & Structures, 1994
This paper attempts to present an algorithm (as a set of conditions and equations) for the correc... more This paper attempts to present an algorithm (as a set of conditions and equations) for the correction of stresses of both strain-hardening and perfectly-plastic materials, for the analysis of frames under transient dynamic loadings. The validity of the proposed conditions and equations is verified through numerical experiments.
Computers & Structures, 1990
A unified approach is presented for the static and transient linear and geometrically non-linear ... more A unified approach is presented for the static and transient linear and geometrically non-linear analyses of two-dimensional problems (plane stress/strain and axisymmetric). A finite element idealization with four-, eight-and nine-noded isoparametric quadrilateral elements is used for space discretization. An explicit central difference time-marching scheme is employed for time integration of the resulting discrete ordinary differential equations. Results of several numerical examples are presented and compared with the available data. A comparative study of the performance of various elements with different damping factors is also presented.
Computers & Structures, 1991
Discrete methods for practical coupled three-dimensional fluid-structure interaction problems are... more Discrete methods for practical coupled three-dimensional fluid-structure interaction problems are developed. A Co explicitly integrated two-dimensional degenerate shell element and a three-dimensional fluid element are coupled to study shell dynamics, fluid transient and coupled shell-fluid interaction problems. The method of partitioning is used to integrate the fluid and shell meshes in a staggered fashion in an optimum manner. Effective explicit-implicit partitioning is shown to achieve high computational efficiency for this type of problem.
The demand for improved structural efficiency in space structures and nuclear reactors has result... more The demand for improved structural efficiency in space structures and nuclear reactors has resulted in the development of a new class of materials, called functionally graded materials (fgMs). fgMs have become one of the major research topics in the mechanics of materials community during the past fifteen years. The concept of FGMs was proposed in 1984 by materials’ scientists in the Sendai (Japan) area as a means of preparing thermal barrier materials1. continuous changes in the composition, microstructure, porosity, etc. of these materials result in gradients in properties such as mechanical strength and thermal conductivity. thus, fgMs are heterogeneous materials, characterized by spatially variable microstructures, and thus spatially variable macroscopic properties are introduced to enhance material or structural performance. Particularly, material properties can be A simplified and accurate analytical cum numerical model is presented here to investigate the behavior of FG cylin...
International Journal of Solids and Structures, 2005
A semi-analytical solution procedure for three dimensional wave propagation in reinforced concret... more A semi-analytical solution procedure for three dimensional wave propagation in reinforced concrete (RC) beams has been presented in this paper. Elastodynamic GreenÕs function has been derived by employing the compatibility conditions and utilizing the symmetry conditions at the loaded cross section. Numerical procedure developed for the GreenÕs function has been validated using results available in the literature for an infinite laminated composite plate. Threedimensional wave propagation analysis has been performed for reinforced concrete beam sections of T and L shapes which are common forms of structural elements. Steel reinforcement has been modeled in the finite element mesh. Effect of corrosion has also been included in the finite element model. GreenÕs function for reinforced concrete sections affected by corrosion of steel unit normalized frequency has been evaluated for illustration. Accuracy of the solution technique has been evaluated in terms of the percentage error in energy balance between the input energy of the applied unit load and the output energy carried by the propagating wave modes. The percentage error has been found to be negligible in all the cases considered here. A simple and accurate numerical method has been presented here as a tool to evaluate GreenÕs function for RC beams and can be used to detect corrosion.
Proceedings of the Indian National Science Academy, 2017
A complete formulation of static and dynamic analysis is presented using higher order shear and n... more A complete formulation of static and dynamic analysis is presented using higher order shear and normal deformation theory (HOSNT) with twelve middle surface displacement parameters for doubly curved shells. Mathematical difficulty of obtaining a three dimensional (3D) solution for problems of plates and shells steered the development of two dimensional (2D) theories. Present model considers transverse shear strains and normal strains thus also incorporating rotary inertia and subsequent higher order expression in dynamic terms. A variational principle based on minimization of energy is used to derive the set of governing differential equations and associated boundary conditions. The theory presented here also uses extended thickness criteria where square of thickness to radius of curvature is considered less than unity instead of the classical assumption of taking thickness to radius of curvature less than unity. Problem of isotropic open cylindrical shell is solved and results are compared with available 3D solutions.
Journal of Sandwich Structures & Materials, 2005
Two higher-order shear deformable finite element models using a higher-order facet shell element ... more Two higher-order shear deformable finite element models using a higher-order facet shell element are presented for the free vibration analysis of layered anisotropic sandwich laminates. One of the higher-order shear deformation models accounts for the effects of both transverse shear strains/stresses and the transverse normal strain/stress, while the other includes only the effects of the transverse shear deformation. The accuracy of the present models is demonstrated by comparing the results of laminated sandwich plates with the available closed- form solutions. Benchmark solutions with the parametric study for the laminated sandwich cylindrical and spherical shell panels are also presented.
Journal of Applied Mechanics, 1990
International Journal for Computational Methods in Engineering Science and Mechanics, 2007
A simple, semi-analytical methodology defining a two-point boundary value problem (BVP) governed ... more A simple, semi-analytical methodology defining a two-point boundary value problem (BVP) governed by a set of linear first-order ordinary differential equations (ODEs) with mixed primary variables whose number equals the order of partial differential equations (PDEs) for narrow layered ...
Communications in Numerical Methods in Engineering, 2006
COMMUNICATIONS IN NUMERICAL METHODS IN ENGINEERING Commun. Numer. Meth. Engng 2008; 24:1532 Publ... more COMMUNICATIONS IN NUMERICAL METHODS IN ENGINEERING Commun. Numer. Meth. Engng 2008; 24:1532 Published online 7 November 2006 in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/cnm.952 ... Stress analyses of laminates ...
Composites Science and Technology, 1988
Advances in Structural Engineering, 2014
ABSTRACT Functionally graded materials (FGMs) are recently developed advanced composite materials... more ABSTRACT Functionally graded materials (FGMs) are recently developed advanced composite materials and are being widely used in various innovative engineering appliances. In recent years FGMs are gaining considerable importance and finding wide applications in high temperature environments, such as, fusion-based nuclear reactors, chemical plants, aerospace structural applications, etc. A mixture of ceramic and metal or, a combination of different materials is used to make FGMs. New methodologies need to be developed for engineering characterization of FGMs with their increase in applications in various fields, and also to analyse and design structural components, viz., beams, plates and shells made of these advanced materials with reasonably high accuracy and computational efforts. In view of above, an accurate higher order shear and normal deformation plate theory is employed for stress and free vibration analyses of functionally graded (FG) elastic, rectangular, and simply supported (diaphragm) plates in the present study. The theoretical model is based on Taylor's series expansion of in-plane and transverse displacements in thickness coordinate defining the plate deformations. FGMs are idealized as continua with mechanical properties changing smoothly with respect to spatial coordinates. The material properties of FG plates are assumed to be varying through thickness of plate in a continuous manner. Poisson’s ratios of FG plates are assumed constant, but their Young’s modulii and densities vary continuously in thickness direction according to the volume fraction of constituents which is modelled here as exponential and power law functions. The effect of variation of material properties in terms of its gradation index on deformations, stresses and natural frequency of FG plates are studied.
IUTAM Symposium on Multi-Functional Material Structures and Systems, 2009
Abstract Estimation of displacements and stresses in functionally graded (FG) beams and plates ar... more Abstract Estimation of displacements and stresses in functionally graded (FG) beams and plates are carried out using higher order shear and normal deformation theories (HOSNTs). Taylor's series expansion is adopted to approximate primary displacements in the thickness ...
Journal of Sound and Vibration, 2011
Journal of Engineering Mechanics, 2011
International Journal of Pressure Vessels and Piping, 1974
for a number of cases and for a given set of values of elastic moduli, Poisson's ratio and thickn... more for a number of cases and for a given set of values of elastic moduli, Poisson's ratio and thickness/diameter ratio. The results are compared with the known results available in literature and also with the stresses predicted by the .4SME Code.
International Journal of Pressure Vessels and Piping, 2004
The performance of the Chaboche kinematic hardening model has been evaluated in this paper to pre... more The performance of the Chaboche kinematic hardening model has been evaluated in this paper to predict the ratchetting responses for a broad set of uniaxial and biaxial loading histories. The investigations have been performed with reference to both uniaxial and biaxial experimental data, viz. (a) strain and stress controlled uniaxial tests on tensile specimens; (b) biaxial tests on straight pipes with constant internal pressure and cyclic bending load; and (c) a shake table test on elbow. The parameters of the Chaboche model have been calculated from the uniaxial strain controlled stable hysteresis loop. Amongst the various parameters in the Chaboche model, it has been found that the selection of the value of g 3 plays a crucial role in achieving better simulation. The Chaboche model was observed to predict complete shakedown for g 3 ¼ 0: On the other hand, the model closely simulated the experimental results for g 3 ¼ 9: The same parameters have been used to analyze the biaxial loading condition. Ratchetting simulation studies by the Chaboche model have resulted in reasonably good agreement with experiments.
International Journal of Pressure Vessels and Piping, 2003
The phenomenon of ratchetting is defined as constant accumulation of plastic strain or deformatio... more The phenomenon of ratchetting is defined as constant accumulation of plastic strain or deformation under combined steady state and cyclic loading. It can reduce the fatigue life or can cause failure of piping components or systems subjected to seismic or other cyclic loads. The uniaxial ratchetting characteristics of SA333 Gr.6 steel have been investigated at room temperature in the present paper. The specimens were subjected to cyclic axial stress with a constant mean stress of 200 MPa and a varying amplitude stress of 149, 174, 199 and 224 MPa. Tests were also performed on 203.2 mm, Sch 80, SA333 Gr. 6 carbon steel straight pipe. The pipe was subjected to a constant internal pressure of 18 MPa and a cyclic bending load. The effects of amplitude of load on the rate of ratchetting have also been investigated in the present paper. The uniaxial experiments showed that specimens exhibited shakedown at low stress amplitude after some strain accumulation. However, specimens experienced continuous ratchetting at higher stress amplitudes with no shakedown before failure. Ovalization of the pipe crosssection was observed when the pipe was subjected to constant internal pressure and cyclic point load. Local bulging was observed at higher loading. The pipe did not show any shakedown behaviour for the given cycles of loading and exhibited continuous ratchetting under the varying amplitude loading.
Engineering Computations, 1988
A C° finite element formulation for flexure‐membrane coupling behaviour of an unsymmetrically lam... more A C° finite element formulation for flexure‐membrane coupling behaviour of an unsymmetrically laminated plate based on a higher‐order displacement model and three‐dimensional state of stress and strain is presented. This theory incorporates the more realistic non‐linear variation of displacements through the plate thickness, thus eliminating the use of a shear correction coefficient. The discrete element chosen is a nine‐noded quadrilateral with 12 degrees of freedom per node. The computer program developed incorporates the realistic prediction of interlaminar stresses from equilibrium equations. The present solution for deflection and stresses is compared with those obtained using three‐dimensional elasticity theory, another higher‐order shear deformation theory and Mindlin theory. In addition, numerical results for unsymmetric sandwich plates are presented for future reference.
Computers & Structures, 1994
Ahatraet-The well-known central difference predictor method used for the analysis of nonlinear sy... more Ahatraet-The well-known central difference predictor method used for the analysis of nonlinear systems, subjected to transient dynamic loads, is modified by incorporating Rayleigh's damping into the governing incremental equation of motion. The new time-stepping scheme requires a starting algorithm for both the first and second time-steps, and can effectively be used to analyse the nonlinear damped systems in general.
Computers & Structures, 1994
This paper attempts to present an algorithm (as a set of conditions and equations) for the correc... more This paper attempts to present an algorithm (as a set of conditions and equations) for the correction of stresses of both strain-hardening and perfectly-plastic materials, for the analysis of frames under transient dynamic loadings. The validity of the proposed conditions and equations is verified through numerical experiments.
Computers & Structures, 1990
A unified approach is presented for the static and transient linear and geometrically non-linear ... more A unified approach is presented for the static and transient linear and geometrically non-linear analyses of two-dimensional problems (plane stress/strain and axisymmetric). A finite element idealization with four-, eight-and nine-noded isoparametric quadrilateral elements is used for space discretization. An explicit central difference time-marching scheme is employed for time integration of the resulting discrete ordinary differential equations. Results of several numerical examples are presented and compared with the available data. A comparative study of the performance of various elements with different damping factors is also presented.
Computers & Structures, 1991
Discrete methods for practical coupled three-dimensional fluid-structure interaction problems are... more Discrete methods for practical coupled three-dimensional fluid-structure interaction problems are developed. A Co explicitly integrated two-dimensional degenerate shell element and a three-dimensional fluid element are coupled to study shell dynamics, fluid transient and coupled shell-fluid interaction problems. The method of partitioning is used to integrate the fluid and shell meshes in a staggered fashion in an optimum manner. Effective explicit-implicit partitioning is shown to achieve high computational efficiency for this type of problem.
The demand for improved structural efficiency in space structures and nuclear reactors has result... more The demand for improved structural efficiency in space structures and nuclear reactors has resulted in the development of a new class of materials, called functionally graded materials (fgMs). fgMs have become one of the major research topics in the mechanics of materials community during the past fifteen years. The concept of FGMs was proposed in 1984 by materials’ scientists in the Sendai (Japan) area as a means of preparing thermal barrier materials1. continuous changes in the composition, microstructure, porosity, etc. of these materials result in gradients in properties such as mechanical strength and thermal conductivity. thus, fgMs are heterogeneous materials, characterized by spatially variable microstructures, and thus spatially variable macroscopic properties are introduced to enhance material or structural performance. Particularly, material properties can be A simplified and accurate analytical cum numerical model is presented here to investigate the behavior of FG cylin...
International Journal of Solids and Structures, 2005
A semi-analytical solution procedure for three dimensional wave propagation in reinforced concret... more A semi-analytical solution procedure for three dimensional wave propagation in reinforced concrete (RC) beams has been presented in this paper. Elastodynamic GreenÕs function has been derived by employing the compatibility conditions and utilizing the symmetry conditions at the loaded cross section. Numerical procedure developed for the GreenÕs function has been validated using results available in the literature for an infinite laminated composite plate. Threedimensional wave propagation analysis has been performed for reinforced concrete beam sections of T and L shapes which are common forms of structural elements. Steel reinforcement has been modeled in the finite element mesh. Effect of corrosion has also been included in the finite element model. GreenÕs function for reinforced concrete sections affected by corrosion of steel unit normalized frequency has been evaluated for illustration. Accuracy of the solution technique has been evaluated in terms of the percentage error in energy balance between the input energy of the applied unit load and the output energy carried by the propagating wave modes. The percentage error has been found to be negligible in all the cases considered here. A simple and accurate numerical method has been presented here as a tool to evaluate GreenÕs function for RC beams and can be used to detect corrosion.
Proceedings of the Indian National Science Academy, 2017
A complete formulation of static and dynamic analysis is presented using higher order shear and n... more A complete formulation of static and dynamic analysis is presented using higher order shear and normal deformation theory (HOSNT) with twelve middle surface displacement parameters for doubly curved shells. Mathematical difficulty of obtaining a three dimensional (3D) solution for problems of plates and shells steered the development of two dimensional (2D) theories. Present model considers transverse shear strains and normal strains thus also incorporating rotary inertia and subsequent higher order expression in dynamic terms. A variational principle based on minimization of energy is used to derive the set of governing differential equations and associated boundary conditions. The theory presented here also uses extended thickness criteria where square of thickness to radius of curvature is considered less than unity instead of the classical assumption of taking thickness to radius of curvature less than unity. Problem of isotropic open cylindrical shell is solved and results are compared with available 3D solutions.