The Experts below are selected from a list of 2313 Experts worldwide ranked by ideXlab platform
Farhang Pourboghrat - One of the best experts on this subject based on the ideXlab platform.
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fourier series based finite element analysis of tube hydroforming Generalized Plane Strain model
Journal of Materials Processing Technology, 2008Co-Authors: Yabo Guan, Farhang PourboghratAbstract:Abstract In previous paper [Fourier series based finite element analysis of tube hydroforming—An axisymmetric model, Eng. Comput. 23 (7) (2006) 697–728], an axisymmetric analysis of tube hydroforming process was discussed. In the present paper, a Generalized Plane Strain implicit formulation of the cross-sectional expansion of an extruded aluminum tube with pressurized fluid to fill a hydroforming die is presented. The cross-section of the tube is modeled with thin straight and circular segments with constant thickness, and Fourier series are used to approximate nodal displacements. The material of the tube is assumed to obey a rate-independent, elastoplastic model that takes into account work hardening and normal anisotropy. At the tube-die interface, frictional stress is assumed, based on Coulomb friction, to be proportional to the contact pressure whenever relative sliding occurs. The kinematics relationships are derived based on thin shell theory, and the equilibrium equation is derived based on virtual work principle. The axial feed is implemented by imposing either a compressive force or Strain in the tube length direction. Frictional boundary condition is introduced into the formulation in the form of a penalty function, which imposes the conStraints directly into the tangent stiffness matrix. The Newton-Raphson iterative method is used to incrementally solve the resulting nonlinear equations. Two examples of tube hydroforming problems are solved and numerical predictions of the deformed shape, hydroforming pressure, and deformation Strains are compared with experimental and ABAQUS results.
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Fourier series based finite element analysis of tube hydroforming—Generalized Plane Strain model
Journal of Materials Processing Technology, 2007Co-Authors: Yabo Guan, Farhang PourboghratAbstract:Abstract In previous paper [Fourier series based finite element analysis of tube hydroforming—An axisymmetric model, Eng. Comput. 23 (7) (2006) 697–728], an axisymmetric analysis of tube hydroforming process was discussed. In the present paper, a Generalized Plane Strain implicit formulation of the cross-sectional expansion of an extruded aluminum tube with pressurized fluid to fill a hydroforming die is presented. The cross-section of the tube is modeled with thin straight and circular segments with constant thickness, and Fourier series are used to approximate nodal displacements. The material of the tube is assumed to obey a rate-independent, elastoplastic model that takes into account work hardening and normal anisotropy. At the tube-die interface, frictional stress is assumed, based on Coulomb friction, to be proportional to the contact pressure whenever relative sliding occurs. The kinematics relationships are derived based on thin shell theory, and the equilibrium equation is derived based on virtual work principle. The axial feed is implemented by imposing either a compressive force or Strain in the tube length direction. Frictional boundary condition is introduced into the formulation in the form of a penalty function, which imposes the conStraints directly into the tangent stiffness matrix. The Newton-Raphson iterative method is used to incrementally solve the resulting nonlinear equations. Two examples of tube hydroforming problems are solved and numerical predictions of the deformed shape, hydroforming pressure, and deformation Strains are compared with experimental and ABAQUS results.
Peter Schiavone - One of the best experts on this subject based on the ideXlab platform.
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Steady-state vibrations of an unbounded linear piezoelectric medium
Zeitschrift für angewandte Mathematik und Physik, 2006Co-Authors: E. Lioubimova, Peter SchiavoneAbstract:We consider fundamental (Dirichlet and Neumann-type) boundary value problems in a theory of Generalized Plane Strain for the steady-state vibrations of an infinite piezoelectric medium with transversely isotropic symmetry (6 mm). Using integral equation methods with the appropriate Sommerfeld-type radiation conditions, we prove existence and uniqueness results for the corresponding exterior boundary value problems. Exact solutions are obtained in the form of integral potentials.
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Steady-state vibrations for the state of Generalized Plane Strain in a linear piezoelectric medium
International Journal of Engineering Science, 2006Co-Authors: E. Lioubimova, Peter SchiavoneAbstract:Abstract In this paper, steady-state vibrations are studied for the state of Generalized Plane Strain in a linear piezoelectric medium. The fundamental boundary value problems are stated for vibrations in a prismatic piezoelectric body with arbitrary cross-section composed of material with the more general, tetragonal 4 ¯ , symmetry . Along with general theory, we present some other useful results concerning the behavior of the matrix of fundamental solutions. The conditions for the critical values of the field quantities on the boundary are derived.
Vadim V. Silberschmidt - One of the best experts on this subject based on the ideXlab platform.
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comparison of Plane stress Generalized Plane Strain and 3d fem elastic plastic analyses of thick walled cylinders subjected to radial thermal gradient
International Journal of Mechanical Sciences, 2017Co-Authors: Seikh Mustafa Kamal, Uday S. Dixit, Anish Roy, Qian Liu, Vadim V. SilberschmidtAbstract:Abstract In many industrial applications, thick-walled cylindrical components are subjected to high pressure and/or temperature. During the operation the cylinder wall may undergo elastic–plastic deformation. This paper presents Plane-stress and Plane-Strain thermo-elastic–plastic stress analyses of thick-walled cylinders subjected to a radial thermal gradient. A three-dimensional finite element method (3D FEM) analysis of the thermo-elastic–plastic stresses in thick-walled cylinder is also carried out. The 3D FEM results are compared with the analytical Plane stress and the Generalized Plane Strain analyses in order to study the validity of these models on the basis of length to wall-thickness ratio of cylinders. The Plane stress and Generalized Plane Strain analyses are based on the Tresca yield criterion and associated flow rule. The Strain hardening behavior of the material of the cylinder is taken into account. It is observed that for the length to wall thickness ratio of more than 6, the Generalized Plane Strain analysis can provide sufficiently accurate results. Similarly, for the length to wall thickness ratio of less than 0.5, Plane stress analysis can be used. When the length to wall thickness ratio is more than 0.5 but less than 6, a three-dimensional analysis is needed.
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Comparison of Plane-stress, Generalized-Plane-Strain and 3D FEM elastic–plastic analyses of thick-walled cylinders subjected to radial thermal gradient
International Journal of Mechanical Sciences, 2017Co-Authors: Seikh Mustafa Kamal, Uday S. Dixit, Anish Roy, Qian Liu, Vadim V. SilberschmidtAbstract:Abstract In many industrial applications, thick-walled cylindrical components are subjected to high pressure and/or temperature. During the operation the cylinder wall may undergo elastic–plastic deformation. This paper presents Plane-stress and Plane-Strain thermo-elastic–plastic stress analyses of thick-walled cylinders subjected to a radial thermal gradient. A three-dimensional finite element method (3D FEM) analysis of the thermo-elastic–plastic stresses in thick-walled cylinder is also carried out. The 3D FEM results are compared with the analytical Plane stress and the Generalized Plane Strain analyses in order to study the validity of these models on the basis of length to wall-thickness ratio of cylinders. The Plane stress and Generalized Plane Strain analyses are based on the Tresca yield criterion and associated flow rule. The Strain hardening behavior of the material of the cylinder is taken into account. It is observed that for the length to wall thickness ratio of more than 6, the Generalized Plane Strain analysis can provide sufficiently accurate results. Similarly, for the length to wall thickness ratio of less than 0.5, Plane stress analysis can be used. When the length to wall thickness ratio is more than 0.5 but less than 6, a three-dimensional analysis is needed.
Yabo Guan - One of the best experts on this subject based on the ideXlab platform.
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fourier series based finite element analysis of tube hydroforming Generalized Plane Strain model
Journal of Materials Processing Technology, 2008Co-Authors: Yabo Guan, Farhang PourboghratAbstract:Abstract In previous paper [Fourier series based finite element analysis of tube hydroforming—An axisymmetric model, Eng. Comput. 23 (7) (2006) 697–728], an axisymmetric analysis of tube hydroforming process was discussed. In the present paper, a Generalized Plane Strain implicit formulation of the cross-sectional expansion of an extruded aluminum tube with pressurized fluid to fill a hydroforming die is presented. The cross-section of the tube is modeled with thin straight and circular segments with constant thickness, and Fourier series are used to approximate nodal displacements. The material of the tube is assumed to obey a rate-independent, elastoplastic model that takes into account work hardening and normal anisotropy. At the tube-die interface, frictional stress is assumed, based on Coulomb friction, to be proportional to the contact pressure whenever relative sliding occurs. The kinematics relationships are derived based on thin shell theory, and the equilibrium equation is derived based on virtual work principle. The axial feed is implemented by imposing either a compressive force or Strain in the tube length direction. Frictional boundary condition is introduced into the formulation in the form of a penalty function, which imposes the conStraints directly into the tangent stiffness matrix. The Newton-Raphson iterative method is used to incrementally solve the resulting nonlinear equations. Two examples of tube hydroforming problems are solved and numerical predictions of the deformed shape, hydroforming pressure, and deformation Strains are compared with experimental and ABAQUS results.
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Fourier series based finite element analysis of tube hydroforming—Generalized Plane Strain model
Journal of Materials Processing Technology, 2007Co-Authors: Yabo Guan, Farhang PourboghratAbstract:Abstract In previous paper [Fourier series based finite element analysis of tube hydroforming—An axisymmetric model, Eng. Comput. 23 (7) (2006) 697–728], an axisymmetric analysis of tube hydroforming process was discussed. In the present paper, a Generalized Plane Strain implicit formulation of the cross-sectional expansion of an extruded aluminum tube with pressurized fluid to fill a hydroforming die is presented. The cross-section of the tube is modeled with thin straight and circular segments with constant thickness, and Fourier series are used to approximate nodal displacements. The material of the tube is assumed to obey a rate-independent, elastoplastic model that takes into account work hardening and normal anisotropy. At the tube-die interface, frictional stress is assumed, based on Coulomb friction, to be proportional to the contact pressure whenever relative sliding occurs. The kinematics relationships are derived based on thin shell theory, and the equilibrium equation is derived based on virtual work principle. The axial feed is implemented by imposing either a compressive force or Strain in the tube length direction. Frictional boundary condition is introduced into the formulation in the form of a penalty function, which imposes the conStraints directly into the tangent stiffness matrix. The Newton-Raphson iterative method is used to incrementally solve the resulting nonlinear equations. Two examples of tube hydroforming problems are solved and numerical predictions of the deformed shape, hydroforming pressure, and deformation Strains are compared with experimental and ABAQUS results.
Seikh Mustafa Kamal - One of the best experts on this subject based on the ideXlab platform.
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Generalized Plane Strain Study of Rotational Autofrettage of Thick-walled Cylinders: Part II- Numerical Evaluation
Journal of Pressure Vessel Technology, 2019Co-Authors: Seikh Mustafa Kamal, Mordechai PerlAbstract:The theoretical modeling of the rotational autofrettage of a thick-walled cylinder based on the Generalized Plane Strain assumption has been presented in part I of the paper. In order to access the potentiality of the proposed theoretical model, the numerical evaluation of the analytical solutions is important. This part of the paper presents numerical evaluation of the Generalized Plane Strain model for typical thick-walled cylinders. The residual hoop stress generated in the rotational autofrettage of a typical gun barrel is compared with the residual hoop stresses in the conventional hydraulic and swage autofrettage processes. Comparison shows that the rotationally autofrettaged gun barrel is capable of producing the same level of compressive residual hoop stress at the inner surface as that of the hydraulic autofrettage. In order to corroborate the analytical solution, a three-dimensional finite element method (3D FEM) analysis of the rotational process is carried out in ANSYS finite element package and the results are compared with the theoretical results. The comparison shows a good matching of the results between the theoretical evaluation and the 3D FEM analysis. Finally, a short feasibility analysis of the rotational autofrettage process of typical cylinders is carried out for the practical realization of the process.
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Generalized Plane Strain Study of Rotational Autofrettage of Thick-Walled Cylinders—Part I: Theoretical Analysis
Journal of Pressure Vessel Technology, 2019Co-Authors: Seikh Mustafa Kamal, Mordechai Perl, Debasish BharaliAbstract:In recent years, a few new methods of achieving autofrettage in thick-walled hollow cylinders have been developed. Rotational autofrettage is one of the new methods proposed recently for prestressing thick-walled cylinders. The principle of rotational autofrettage is based on inducing plastic deformation in the cylinder at the inner side and at its neighborhood by rotating the cylinder about its own axis at a certain angular velocity and subsequently bringing down it to zero angular velocity. However, the analysis of the process is still in its nascent stage. In order to establish the rotational autofrettage as a potential design procedure for prestressing thick-walled cylinders, accurate modeling of the process is necessary. In this paper, the rotational autofrettage for thick-walled cylinders is analyzed theoretically based on the Generalized Plane Strain assumption. The closed form analytical solutions of the elasto-plastic stresses and Strains and the residual stresses after unloading during the rotational autofrettage of a thick-walled cylinder are obtained. In Part II of the paper, the numerical evaluation of the theoretical model will be presented in order to assess its feasibility.
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comparison of Plane stress Generalized Plane Strain and 3d fem elastic plastic analyses of thick walled cylinders subjected to radial thermal gradient
International Journal of Mechanical Sciences, 2017Co-Authors: Seikh Mustafa Kamal, Uday S. Dixit, Anish Roy, Qian Liu, Vadim V. SilberschmidtAbstract:Abstract In many industrial applications, thick-walled cylindrical components are subjected to high pressure and/or temperature. During the operation the cylinder wall may undergo elastic–plastic deformation. This paper presents Plane-stress and Plane-Strain thermo-elastic–plastic stress analyses of thick-walled cylinders subjected to a radial thermal gradient. A three-dimensional finite element method (3D FEM) analysis of the thermo-elastic–plastic stresses in thick-walled cylinder is also carried out. The 3D FEM results are compared with the analytical Plane stress and the Generalized Plane Strain analyses in order to study the validity of these models on the basis of length to wall-thickness ratio of cylinders. The Plane stress and Generalized Plane Strain analyses are based on the Tresca yield criterion and associated flow rule. The Strain hardening behavior of the material of the cylinder is taken into account. It is observed that for the length to wall thickness ratio of more than 6, the Generalized Plane Strain analysis can provide sufficiently accurate results. Similarly, for the length to wall thickness ratio of less than 0.5, Plane stress analysis can be used. When the length to wall thickness ratio is more than 0.5 but less than 6, a three-dimensional analysis is needed.
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Comparison of Plane-stress, Generalized-Plane-Strain and 3D FEM elastic–plastic analyses of thick-walled cylinders subjected to radial thermal gradient
International Journal of Mechanical Sciences, 2017Co-Authors: Seikh Mustafa Kamal, Uday S. Dixit, Anish Roy, Qian Liu, Vadim V. SilberschmidtAbstract:Abstract In many industrial applications, thick-walled cylindrical components are subjected to high pressure and/or temperature. During the operation the cylinder wall may undergo elastic–plastic deformation. This paper presents Plane-stress and Plane-Strain thermo-elastic–plastic stress analyses of thick-walled cylinders subjected to a radial thermal gradient. A three-dimensional finite element method (3D FEM) analysis of the thermo-elastic–plastic stresses in thick-walled cylinder is also carried out. The 3D FEM results are compared with the analytical Plane stress and the Generalized Plane Strain analyses in order to study the validity of these models on the basis of length to wall-thickness ratio of cylinders. The Plane stress and Generalized Plane Strain analyses are based on the Tresca yield criterion and associated flow rule. The Strain hardening behavior of the material of the cylinder is taken into account. It is observed that for the length to wall thickness ratio of more than 6, the Generalized Plane Strain analysis can provide sufficiently accurate results. Similarly, for the length to wall thickness ratio of less than 0.5, Plane stress analysis can be used. When the length to wall thickness ratio is more than 0.5 but less than 6, a three-dimensional analysis is needed.