The Experts below are selected from a list of 636 Experts worldwide ranked by ideXlab platform
Weiyuan Zhou - One of the best experts on this subject based on the ideXlab platform.
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shear banding analysis of geomaterials by strain gradient enhanced damage model
International Journal of Solids and Structures, 2005Co-Authors: Jidong Zhao, Daichao Sheng, Weiyuan ZhouAbstract:Shear band localization is investigated by a strain-gradient-enhanced damage model for quasi-brittle geomaterials. This model introduces the strain gradients and their higher-order conjugate stresses into the framework of continuum damage mechanics. The influence of the strain gradients on the constitutive behaviour is taken into account through a generalized damage evolutionary law. A weak-form variational principle is employed to address the additional boundary conditions introduced by the incorpoRation of the strain gradients and the conjugate higher-order stresses. Damage localization under simple shear condition is analytically investigated by using the theory of discontinuous bifurcation and the concept of the second-order characteristic surface. Analytical solutions for the distributions of strain rates and strain gradient rates, as well as the band width of localised damage are found. Numerical analysis demonstrates the shear band width is proportionally related to the internal length scale through a coefficient function of Poissons Ratio and a parameter representing the shape of uniaxial stress–strain curve. It is also shown that the obtained distributions of strains and strain gradients are well in accordance with the underlying assumptions for the second-order discontinuous shear band boundary and the weak discontinuous bifurcation theory. 2005 Elsevier Ltd. All rights reserved.
H Baruh - One of the best experts on this subject based on the ideXlab platform.
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a closed form solution procedure for circular cylindrical shell vibRations
International Journal of Solids and Structures, 1999Co-Authors: Joseph T Callahan, H BaruhAbstract:Abstract A systematic procedure for obtaining the closed-form eigensolution for thin circular cylindrical shell vibRations is presented, which utilizes the computational power of existing commercial software packages. For cylindrical shells, the longitudinal, radial, and circumferential displacements are all coupled with each other due to Poissons Ratio and the curvature of the shell. For beam and plate vibRations, the eigensolution can often be found without knowledge of absolute dimensions or material properties. For cylindrical shell vibRations, however, one must know the relative Ratios between shell radius, length, and thickness, as well as Poissons Ratio of the material. The mode shapes and natural frequencies can be determined analytically to within numerically determined coefficients for a wide variety of boundary conditions, including elastic and rigid ring stiffeners at the boundaries. Excellent agreement is obtained when the computed natural frequencies are compared with known experimental results.
Bhavani V Sankar - One of the best experts on this subject based on the ideXlab platform.
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analysis of sandwich tps panel with functionally graded foam core by galerkin method
Composite Structures, 2007Co-Authors: H Zhu, Bhavani V SankarAbstract:The method of Fourier analysis is combined with the Galerkin method for solving the two-dimensional elasticity equations for a sandwich thermal protection system (TPS) insulation panel with foam core subjected to transverse loads. The variation of the Youngs modulus through the thickness is given by a polynomial in the thickness coordinate and the Poissons Ratio is assumed to be constant. The Fourier series method is used to reduce the partial differential equations to a pair of ordinary differential equations, which are solved by using the Galerkin method. The method will be useful in analyzing functionally graded TPS structures with arbitrary variation of thermomechanical properties in the thickness direction. The analysis was also performed using sandwich plate theory. Significant differences were found in the results suggesting that the sandwich theory may not be suitable for the analysis of thick sandwich TPS panel. 2005 Elsevier Ltd. All rights reserved.
Jidong Zhao - One of the best experts on this subject based on the ideXlab platform.
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shear banding analysis of geomaterials by strain gradient enhanced damage model
International Journal of Solids and Structures, 2005Co-Authors: Jidong Zhao, Daichao Sheng, Weiyuan ZhouAbstract:Shear band localization is investigated by a strain-gradient-enhanced damage model for quasi-brittle geomaterials. This model introduces the strain gradients and their higher-order conjugate stresses into the framework of continuum damage mechanics. The influence of the strain gradients on the constitutive behaviour is taken into account through a generalized damage evolutionary law. A weak-form variational principle is employed to address the additional boundary conditions introduced by the incorpoRation of the strain gradients and the conjugate higher-order stresses. Damage localization under simple shear condition is analytically investigated by using the theory of discontinuous bifurcation and the concept of the second-order characteristic surface. Analytical solutions for the distributions of strain rates and strain gradient rates, as well as the band width of localised damage are found. Numerical analysis demonstrates the shear band width is proportionally related to the internal length scale through a coefficient function of Poissons Ratio and a parameter representing the shape of uniaxial stress–strain curve. It is also shown that the obtained distributions of strains and strain gradients are well in accordance with the underlying assumptions for the second-order discontinuous shear band boundary and the weak discontinuous bifurcation theory. 2005 Elsevier Ltd. All rights reserved.
Joseph T Callahan - One of the best experts on this subject based on the ideXlab platform.
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a closed form solution procedure for circular cylindrical shell vibRations
International Journal of Solids and Structures, 1999Co-Authors: Joseph T Callahan, H BaruhAbstract:Abstract A systematic procedure for obtaining the closed-form eigensolution for thin circular cylindrical shell vibRations is presented, which utilizes the computational power of existing commercial software packages. For cylindrical shells, the longitudinal, radial, and circumferential displacements are all coupled with each other due to Poissons Ratio and the curvature of the shell. For beam and plate vibRations, the eigensolution can often be found without knowledge of absolute dimensions or material properties. For cylindrical shell vibRations, however, one must know the relative Ratios between shell radius, length, and thickness, as well as Poissons Ratio of the material. The mode shapes and natural frequencies can be determined analytically to within numerically determined coefficients for a wide variety of boundary conditions, including elastic and rigid ring stiffeners at the boundaries. Excellent agreement is obtained when the computed natural frequencies are compared with known experimental results.