In this paper a robust and efficient methodology is presented for treating large-scale reliability-based, structural optimization problems. The optimization part is performed with evolution strategies, while the reliability analysis is carried out with the Monte Carlo simulation (MCS) method incorporating the importance sampling technique for the reduction of the sample size. The elasto-plastic...

This work presents a finite element study of elasto-plastic hemispherical contact. The results are normalized such that they are valid for macro contacts (e.g., rolling element bearings) and micro contacts (e.g., asperity contact). The material is modeled as elastic-perfectly plastic. The numerical results are compared to other existing models of spherical contact, including the fully plastic c...

We present a numerical method for computing elasto-plastic ows in metals. The method uses a conservative Eulerian formulation of elasto-plasticity together with a higher-order Godunov nite diierence method combined with tracking of material boundaries. The Eulerian approach avoids the problem of mesh distortion caused by a Lagrangian remap, and can be easily extended to the computation of ows i...

— Under some reasonable smoothness assumpfions on the displacements, we are able to dérive an error estimate of the form ||a — <7h||L2{fl)^ Ch, for the approximation of the stress field a in some problems in elasto-plasticity. Using the same ideas, we als o find a piecewise line ar approximation of Mosolov's problem, for which we still get an 0 (h) error estimate.

FGM components are generally constructed to sustain elevated temperatures and severe temperature gradients. Low thermal conductivity, low coefficient of thermal expansion and core ductility have enabled the FGM material to withstand higher temperature gradients for a given heat flux. Examples of structures undergo extremely high temperature gradients are plasma facing materials, propulsion syst...

Three-dimensional nonlinear thermal and thermo-mechanical numerical simulations are conducted for the friction stir welding (FSW) of 304L stainless steel. The finite element analysis code—WELDSIM, developed by the authors specifically for welding simulation, was used. Two welding cases with tool rotational speeds of 300 and 500 rpm are analyzed. The objective is to study the variation of transi...

In the die design of high pressure casting (HPDC), in order to prevent from warpage, it is essential predict ejection force each ejector pin before locating it. Recently, Shiga et al. revealed that their developed elasto-plastic-creep model more accurate than conventional elasto-plastic models estimate thermal stress during cooling with constraint dies.