The initiation and propagation of adiabatic shear bands (ASBs) in functionally graded materials (FGMs) deformed at high strain rates in plane-strain tension have been studied. An ASB is a narrow region, usually a few micrometers wide, of intense plastic deformation that forms after softening of the material due to its being heated up and the evolution of damage in the form of porosity has overc...

The mechanical response of Polyethylene Terephthalate (PET) in elongation is strongly dependent on temperature, strain and strain rate. Near the glass transition temperature Tg, the stress-strain curve presents a strain softening effect vs strain rate but a strain hardening effect vs strain under conditions of large deformations. The main goal of this work is to propose a viscoelastic model to ...

The mechanical response of Polyethylene Terephthalate (PET) in elongation is strongly dependent on temperature, strain and strain rate. Near the glass transition temperature Tg, the stress-strain curve presents a strain softening effect vs strain rate but a strain hardening effect vs strain under conditions of large deformations. The main goal of this work is to propose a viscoelastic model to ...

Indentation is a new method for estimating residual stress. The plastic behavior of the materials under study can affect indentation parameters and, thus, influences the results of residual stress measurement. In this paper, the effect of yield stress and work-hardening exponent on the accuracy of residual stress measurements in steels and aluminums was studied. Results showed that, for m...

A novel variable temperature rolling (VTR) and annealing process was conducted on a metastable austenitic stainless steel. Strain softening occurred during tensile straining in both cold rolled cryogenic rolled-annealed steels, leading to low uniform elongations of only 2-3%. In contrast, thanks the dual-phase heterogeneous lamellar structure achieved via VTR process, ultra-high strength over 1...

This paper presents a methodology to simulate the strain-softening-hardening response of sensitive clays when subjected extensive remoulding. A non-local strain-softening technique is implemented into Abaqus Finite Element Analysis (FEA) software through its user defined material subroutine UMAT, in form critical state based constitutive model. For comparison conventional and formulations, seri...

Hysteretic and nonlinear dielectric behaviour in ferroelectric ceramics has been of interest since 1950s, when these materials found application in various electronic devices. Presently, these phenomena concern with important areas of science, technology and engineering. In particular, nonlinearity and hysteresis are the key factors in performance, precision and accuracy of modern devices. Many...