in this paper, the effect of autofrettage process parameters on the ultimate pressure that functionally graded spherical vessel can tolerate are investigated. fgm properties and autofrettage pressure are considered as important parameters. assumptions are variation of properties of fgm in radial direction, the residual stress in the absence of bauschinger effect with the operation of variable m...

Non-associative elasto-plasticity is the working model of plasticity for soil and rock mechanics. Yet, it is usually viewed as non-variational. In this work, we prove a contrario the existence of a variational evolution for such a model under a natural capping assumption on the hydrostatic stresses and a less natural mollification of the stress admissibility constraint. The obtained elasto-plas...

We use considerations of energy balance and dissipation to derive a self-consistent version of the shear-transformation-zone (STZ) theory of plastic deformation in amorphous solids. The theory is generalized to include arbitrary spatial orientations of STZs. Continuum equations for elasto-plastic material and their energy balance properties are discussed.

During heat treatment, the work piece experiences a range of heating rates depending upon the sizes and types of furnace. When the Al-Si-Mg cast alloy is heated to the solutionizing temperature , recrystallization takes place during the ramp-up stage. The effect of heating rate on recrystallization in the A356 (Al-Si-Mg) alloy was studied using dilatometric and calorimetric methods. Recrystalli...

A new approach for generating stress-constrained topological designs in continua is presented. The main novelty is in the use of elasto-plastic modeling and in optimizing the design such that it will exhibit a linear-elastic response. This is achieved by imposing a single global constraint on the total sum of equivalent plastic strains, providing accurate control over all local stress violation...

in this research a new approach is proposed for elasto-plastic analysis of structures with truss elements. this method covers both perfectly plastic and hardening properties. the proposed technique uses substituting virtual loads instead of modifying the stiffness matrix. to solve this kind of problems, complementary programming is utilized. numerical examples demonstrate that elastoplastic ana...

In this note we investigate the question of higher regularity up to the boundary for quasilinear elliptic systems which origin from the time-discretization of models from infinitesimal elasto-plasticity. Our main focus lies on an elasto-plastic Cosserat model. More specifically we show that the time discretization renders H-regularity of the displacement and H-regularity for the symmetric plast...

57 A methodology for interpreting instrumented sharp indentation with dual sharp indenters with different tip apex 58 angles is presented by recourse to computational modeling within the context of finite element analysis. The forward 59 problem predicts an indentation response from a given set of elasto-plastic properties, whereas the reverse analysis 60 seeks to extract elasto-plastic propert...

Macroscopically heterogeneous materials, characterised mostly by comparable heterogeneity lengthscale and structural sizes, can no longer be modelled by deterministic approach instead. It is convenient to introduce stochastic approach with uncertain material parameters quantified as random fields and/or random variables. The present contribution is devoted to propagation of these uncertainties ...