The compressive creep and recovery of foam earplugs was studied at various applied stresses leading to different fi nal creep strains. Deformation was determined from digital videos of the earplugs via image processing software. Creep could not be modeled by a single exponential in time; creep approximated a power law in time. Nonlinear viscoelasticity was observed: creep compliance depends on ...

The effect of substituting 0.01 at.% Er for Sc in an Al–0.06Zr–0.06Sc–0.04Si (at.%) alloy subjected to a two-stage aging treatment (4 h/300 C and 8 h/425 C) is assessed to determine the viability of dilute Al–Si–Zr–Sc–Er alloys for creep applications. Upon aging, coherent, 2–3 nm radius, L12-ordered, trialuminide precipitates are created, consisting of an Erand Sc-enriched core and a Zr-enriche...

This paper proposes a three-dimensional electromigration model for void evolution in small scale interconnects. Concurrent kinetics of creep flow and surface diffusion as well as the effect of the surrounding material is considered to provide better understanding of the evolution process. The multiple kinetics and energetics are incorporated into a diffusive interface model. A semi-implicit Fou...

A numerical model of a muscle fiber as 400 sarcomeres, identical except for their initial lengths, was used to simulate fixed-end tetanic contractions of frog single fibers at sarcomere lengths above the optimum. The sarcomeres were represented by a lumped model, constructed from the passive and active sarcomere length-tension curves, the force-velocity curve, and the observed active elasticity...

All three burning plasma experiments discussed at Snowmass during the summer of 2002, use preloaded structures to resist some component of the operating loads. For the resistive pulsed reactors, it is the preloads which introduce the most noticeable creep responses because these loads are applied for much longer than the operating loads. If the preloads are maintained during shut-down and maint...

In order to characterize the creep behaviors of 2219 aluminum alloy at different temperatures and stress levels, a RWS-50 Electronic Creep Testing Machine (Zhuhai SUST Electrical Equipment Company, Zhuhai, China) was used for creep experiment at temperatures of 353~458 k and experimental stresses of 130~170 MPa. It was discovered that this alloy displayed classical creep curve characteristics i...

Abstract The slowdown of pressure solution creep has been thought to be caused by stress redistribution. This study presents a fresh view towards this behaviour. Basically, two rate-limiting mechanisms come into play amid creep: (1) redistribution across expanding inter-granular contacts and (2) solute accumulation in the water film. Because non-hydrostatic dissolution occurs under open system ...

Investigation of vortex pinning and its relaxation is of great importance for both basic physics and technological applications in the field of superconductivity. We report a great improvement of superconducting properties in the recently discovered 112-type superconductors (Ca, La)FeAs2 through Co co-doping. High critical current density Js(5 K) > 2(*)10(6) A/cm(2) is obtained and pronounced s...

a r t i c l e i n f o a b s t r a c t The dynamics of wheel shimmy is studied when the self-excited vibrations are related to the elasticity of the tyre. The tyre is described by a classical stretched string model, so the tyre-ground contact patch is approximated by a contact line. The lateral deformation of this line is given via a nonholonomic constraint, namely, the contact points stick to t...

We have studied numerically the dynamics of a driven elastic interface in a random medium, focusing on the thermal rounding of the depinning transition and on the behavior in the T = 0 pinned phase. Thermal effects are quantitatively more important than expected from simple dimensional estimates. For sufficient low temperature the creep velocity at a driving force equal to the T = 0 depinning f...