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The influence of anisotropic properties and layering of saturated soils on dynamic response of a circular foundation under time-harmonic vertical loading is studied in this paper. The foundation is modeled as a rigid disk, with either permeable or impermeable and smooth contact surface, whereas a multilayered transversely isotropic poroelastic half-space is defined for the supporting soil. To investigate the dynamic interaction problem, a displacement and flow boundary condition at the contact surface is constituted by employing a discretization technique and the displacement influence functions, which are obtained from the exact stiffness matrix scheme, with the stiffness matrices being presented explicitly for the first time. A set of numerical results are presented to portray the effects of anisotropic and poroelastic properties, hydraulic boundary conditions, soil heterogeneity, and frequency of excitation on vertical dynamic response of rigid circular foundations. In addition, vertical vibrations of a ring foundation and a massive circular foundation are also investigated.

Changes of ultrasonic wave velocities along the thickness direction of TMCP rolled steel plates are examined. Shear velocities that depend on both propagation and polarization directions are emphasized. Microscopic observation of two vertical planes of steel plate was performed. The effect of grain shape on the ultrasonic shear velocity was studied. For generality, study was conducted on both thick (40 mm thick) and thin (26 mm thick) steel plates. In addition, surface wave velocities were measured at plate surface and center. The results showed that the rolled steel plate exhibits the changes of the shear wave velocities in the thickness direction of the plate. The changes are reasoned to be due to changes in microstructure of the steel plate. Moreover, the high anisotropy is found in the near surface zone of the rolled steel plate.

The usual assumption of isotropy of the material is shown here to be one of the reasons for the observed disparity between the theoretical and experimental values of the critical stress for plastic buckling of plates and shells. When the effect of plastic anisotropy that commonly occurs in thin-walled structures is included in the theoretical framework, the predicted load at the point of bifurcation can be significantly lower than that corresponding to the isotropic material. The present paper is intended to demonstrate the influence of plastic anisotropy on the critical stress for the elastic/plastic buckling of rectangular plates under unidirectional compression. The results are presented graphically to indicate how the critical stress is lowered by the presence of plastic anisotropy that is characterized by an R- value less than unity.

We present a full constitutive relation of silicon steel which can describe the anisotropy effect as well. Using a pilot rolling machine, initial silicon strip with thickness of 2.5mm is rolled into sheet with several thicknesses as reduction ratio increases from 10% to 90%. To examine the effect of anisotropy on the stress-strain behavior, the specimen was cut out from the sheet so that the direction of specimen and sheet is 0°, 30°, 45°, 60° and 90°, respectively. A series of tensile test are then performed with the specimens. The stress-strain curves computed from the proposed constitutive relation are compared with the experimental data. Results show that the predicted curves are in overall in a good agreement with measured ones. The work hardening and unstable softening behaviors of silicon steel during rolling are predicted by the proposed full constitutive relation.

In this study, the FEM material model based on the crystal plasticity is introduced for the numerical simulation of deep drawing process of A5052 aluminum alloy sheet. For calculating the deformation and stress in a crystal of aluminum alloy sheet, Taylor's model is employed. To find the texture evolution, the crystallographic orientation is updated by computing the crystal lattice rotation. In order to verify the crystal plasticity-based FEM material model, the strain distribution and the draw-in amount are compared with experimental measurements. The crystal FEM strains agree well with measured strains. The comparison of draw-in amount shows less 1.96% discrepancy. Texture evolution depends on the initial texture.