This work presents modeling of experiments on a balanced biaxial (BB) pre-strained AA5754 alloy, subsequently reloaded uniaxially along the rolling direction and transverse direction. The material exhibits a complex plastic deformation response during the change in strain path due to 1) crystallographic texture, 2) aging (interactions between dislocations and Mg atoms) and 3) recovery (annihila...

We investigate the transient viscoelastic response of weakly strain-hardening fluids to imposed elongational deformation in filament stretching devices. We combine timedependent finite-element simulations with quantitative experimental measurements on a rheologically well-characterized test fluid to investigate how well the device reproduces the ideal transient uniaxial extensional viscosity pr...

Glassy polymers show "strain hardening": at constant extensional load, their flow first accelerates, then arrests. Recent experiments have found this to be accompanied by a striking and unexplained dip in the segmental relaxation time. Here we explain such behavior by combining a minimal model of flow-induced liquefaction of a glass with a description of the stress carried by strained polymers,...

A simple theory for glassy-polymeric mechanical response that accounts for large-scale chain relaxation is presented. It captures the crossover from perfect-plastic response to Gaussian strain hardening as the degree of polymerization N increases, without invoking entanglements. By relating hardening to interactions on the scale of monomers and chain segments, we correctly predict its magnitude...

Simulations are used to examine the microscopic origins of strain hardening in polymer glasses. While stress-strain curves for a wide range of temperature can be fit to the functional form predicted by entropic network models, many other results are fundamentally inconsistent with the physical picture underlying these models. Stresses are too large to be entropic and have the wrong trend with t...

In ichnology, the Goldilocks effect describes a scenario in which a substrate must be 'just right' in order for tracks to form-too soft, the animal will be unable to traverse the area, and too firm, the substrate will not deform. Any given substrate can therefore only preserve a range of tracks from those animals which exert an underfoot pressure at approximately the yield strength of the sedim...

It is well known that size effects are present in plasticity with the observation that smaller being the stronger. This effect is attributed to the presence of geometrically necessary dislocations (GNDs). The hardening associated to GNDs can be separated in two groups: energetic and dissipative. The fi rst is associated with defect energy and different defi nitions for it are possible. In all c...

The aim of the present study is the prediction of critical conditions (including critical strain and flow stress) for the initiation of dynamic recrystallization during thermo-mechanical processing of plain carbon steels. For this propose, torsion tests were conducted at different temperature (1050, 1100 and 1150˚C) and strain rates (0.002, 0.02 and 0.2/s). All flow curves showed a peak st...

The brass tubes with foam cores of AlSi7SiC3, AlSi7SiC3Fe1 and AlSi7SiC3Fe3 were produced as the crush-boxes with circle and square cross-section. Then axial compressive behavior and energy absorption capability of the foam-filled tubes were investigated during the quasi-static progressive plastic buckling. The uniaxial compressive stress–strain curves of the foam-filled brass tubes exhibited t...