In this paper, the normal stress distribution function along the failure surface in soil obeying general nonlinear failure criterion is first derived, and then a method for calculating the static and ...seismic active earth pressure for soils obeying nonlinear failure criteria is proposed. The method proposed yields not only the active earth pressure and its action point, but also the failure surface and the stress distribution along it. Results of the calculated examples by the proposed method are more reasonable than those reported in the literature. The influence of the parameters of the nonlinear failure criterion on the active earth pressures is also investigated.
In this paper a new theory of effective mechanical properties of foam materials is proposed. A cell volume distribution coefficient is introduced to modify the original Gibson-Ashby equations of ...effective mechanical properties of foam materials. The constants that influence the effective modulus are replaced by the coefficient. Based on the modified distribution coefficient, the yield stress is also recalculated. Using X-ray microtomography, the internal structures of different samples of polypropylene-nanoclay foam are obtained. The cell volume distributions of these samples are derived from the experiment by image analysis and the fitting curves are plotted. The distribution coefficient is acquired using the parameters from the theoretical model of the distribution curves. The results of the improved theory are compared with the experimental values and show good fitting quality. It was found that the precision of the improved theory is high and the cell volume distribution has an impact on the effective mechanical properties that would lead to the optimization of the synthesis procedure.
Modern methods used to estimate the loading of power equipment elements and their lifetime, which may decrease to an essential extent due to temperature pulsations and vibration loads that are ...sometimes inherent in the working process in power equipment, and which may lead to equipment failures. Procedures for calculating the longevity of power equipment elements experiencing temperature pulsations during their operation are proposed.
•A fully-coupled implicit thermo-mechanical model for LFW has been developed.•Model employs semi-automatic re-meshing to accommodate large deformation.•Model is validated by the multi-detector ...polychromatic synchrotron X-ray data.•A general function to describe the Residual Stresses (RS) distribution is provided.•A characteristic length scale is found in the RS distribution function.
In the present study, the residual stresses distribution in the Linear Friction Welded (LFW) pieces were studied using Finite Element (FE) simulation and high energy synchrotron X-ray diffraction. Fully-coupled implicit thermo-mechanical analysis simulation procedure was employed, with semi-automatic re-meshing using Python scripting to accommodate large deformation and output contour tracking methods for extracting deformed configurations. Model validated by the multi-detector polychromatic synchrotron X-ray experimental data were used to study the distribution of residual stresses distribution in the Linear Friction Welded (LFW) pieces to provide a general function to describe the residual stresses distribution. A characteristic length scale was found in the plot.
