Severe surface roughening during the hydroforming of aluminum alloy parts can produce surface defects that severely restrict their application in the automobile and aerospace industry. To understand the relation between strain, grain size and surface roughness under biaxial stress conditions, hydro-bulging tests of aluminum alloy tubes were carried out, and the tubes with different grain sizes ...

On the basis of the pseudopotential plane-wave(PP-PW) method in combination with the local-density-functional theory(LDFT), complete stress-strain curves for the uniaxial loading and uniaxial deformation along the [001] and [111] directions, and the biaxial proportional extension along [010] and [001] of aluminium are obtained. During the uniaxial loading, certain general behaviors of energy ve...

The crystal plasticity finite element method (CPFEM) is used to investigate the coupling between cylindrical void growth or collapse and grain refinement in face-centered cubic (FCC) single crystals. A 2D plane strain model with one used. effect of initial lattice orientation, similarities, differences stress- strain-driven loading scenarios are explored. To this end, boundary conditions enforc...

The rare molybdenum resources are being increasingly used in heavy industries. In this study, the common unidirectional and cross hot rolling operations, for pure plates, were numerically simulated by using MSC. Marc software. An elastic–plastic finite element model was employed, together with updated Lagrange method, to predict stress strain fields workpiece. results showed that there a typica...

Among all directions available for dislocation emission from the surface of a cylindrical circular void, the direction of the most likely emission is determined. It is shown that this direction is different from the direction of the maximum shear stress at the surface of the void due to the applied loading. The critical stress and the direction of the dislocation emission are determined for cir...

Microscale Laser Shock Peening (LSP), also known as Laser Shock Processing, is a technique that can be potentially applied to manipulate residual stress distributions in metal film structures and thus improve the fatigue performances of micro-devices made of such films. In this study, microscale LSP of copper films on single crystal silicon substrate is investigated. Before and after-process cu...

In this article, we develop a new implicit constitutive relation, which is based on thermodynamic foundation that relates the Hencky strain to Cauchy stress, by assuming structure for Gibbs potential stress. We study tension/compression of cylinder, biaxial stretching thin plate and simple shear within context our relation. then compare predictions relation Ogden’s with experiments Treloar conc...

We systematically investigate the incremental response of various equilibrium states of dense 2D model granular materials, along the biaxial compression path (σ11 < σ22, σ12 = 0). Stress increments are applied in arbitrary directions in 3dimensional stress space (σ11,σ22,σ12). In states with stable contact networks we compute the stiffness matrix and the elastic moduli, and separate elastic and...

Endothelial cells (ECs) are continuously exposed in vivo to cyclic strain and shear stress from pulsatile blood flow. When these stimuli are applied in vitro, ECs adopt an appearance resembling their in vivo state, most apparent in their alignment (perpendicular to uniaxial strain and along the flow). Uniaxial strain and flow perpendicular to the strain, used in most in vitro studies, only repr...

Lightweighting materials (e.g., advanced high strength steels, aluminum alloys etc.) are increasingly being used by automotive companies as sheet metal components. However, accurate material models are needed for wider adoption. These constitutive material data are often developed by applying biaxial strain paths with cross-shaped (cruciform) specimens. Optimizing the design of specimens is a m...