in this article, the effects of adding zn and conducting age hardening treatment on impression creep properties of mg-5%sn alloy have been investigated. the creep tests were carried out using impression creep method in which a cylindrical punch was used to apply the stress in range of 450 mpa < σimp < 270 mpa and at the test temperatures of 150, 175 and 200 °c. the results showed that age harde...

We consider three-dimensional nonlinear viscoelastic models that account for both stress relaxation and creep/recovery phenomena. These are based on different frame indifferent time derivatives: the Oldroyd (or upper-convected) derivative, Jaumann co-rotational) derivative Cotter–Rivlin lower-convected) derivative. Under a simple tension creep process, these constitutive equations predict same ...

Viscoelastic properties of woven composite substrates are essential to design dimensionally stable multilayer printed circuit boards. Unlike most existing numerical work which rely on simplified constitutive (elastic) and geometrical models, this study involves a fully three-dimensional viscoelastic model of a plain weave composite with accurate characterization of the woven geometry. Compariso...

Recently, Morner discussed his model of glacio-isostatic compensation in the light of new seismological models of the upper mantle below Fennoscandia (Miimer, 1990). He concluded that the P-wave velocity distribution is in “full agreement” with his estimate of the viscosity distribution as inferred from glacio-isostatic relaxation. Whereas the consistency of seismological and geodynamical earth...

In this paper, we quantify several perceptual capabilities of the human tactile system needed for teletaction. We develop a model of a teletaction system based on predicted subsurface strain. Psychophysics experiments measure the amplitude resolution of the human tactile system, the effects of shear stress on grating orientation discrimination, and the effects of viscoelasticity (creep and rela...

The effects of temperature and pre-strain levels on the stress relaxation behavior corresponding microstructural evolutions Ti-6Al-4V alloys have been investigated experimentally numerically in this study. A series tests (stress (SR) repeated (RSR)) observations (scanning electron microscope) performed, based which deformation-related variables, i.e., component activation energy, as a function ...

This work is an attempt to apply conventional mechanical testing to characterize the photoinduced viscoelastic behavior of chalcogenide glasses. Creep or relaxation-recovery experiments are usually performed to characterize the delayed elastic contribution to deformation, during thermally activated flow. In this paper, relaxation-recovery is used to characterize delayed elasticity under irradia...

Poisson’s ratio in viscoelastic solids is in general a time dependent (in the time domain) or a complex frequency dependent quantity (in the frequency domain). We show that the viscoelastic Poisson’s ratio has a different time dependence depending on the test modality chosen; interrelations are developed between Poisson’s ratios in creep and relaxation. The difference, for a moderate degree of ...

The problem of bounding the total creep (or total stress relaxation) of a composite made of two linear viscoelastic materials and subjected to a constant hydrostatic or antiplane loading is considered. It is done by coupling the immediate and the relaxed responses of the composite, which are pure elastic. The coupled bounds provide the possible range of the total deformation at infinite time as...