SUMMARY c The concept that creep response is the result of a transient approach to a minimum strain rate continuously modified by accumulating damage has been investigated using high precision creep data. It was considered that the accumulated creep strain might be some measure of internal damage and curves of log creep strain rate against creep strain are shown to exhibit linearity at higher s...

Modelling fuel behaviour requires an accurate description of the cladding stress response for both operational and safety considerations. The transient creep response of Zirconium alloys is commonly modelled using a strain hardening rule which is known to hold in cases with monotonously increasing stresses. However, the strain hardening rule is experimentally known to fail in scenarios such as ...

Cyclic plasticity and creep are the primary design considerations of 1 and 2 stage gas turbine blades. Directionally-solidified (DS) Ni-base materials have been developed to provide (1) greater creep ductility and (2) lower minimum creep rate in solidification direction compared to other directions. Tracking the evolution of deformation in DS structures necessitates a constitutive model having ...

Time dependent plastic deformation in metals can occur at high temperatures. Typically the creep test is conducted to characterize the deformation features; however, the conventional uniaxial power-law creep test may be impractical for small scale materials. Accordingly, instrumented indentation techniques are frequently employed. This study concerns the employment of instrumented indentation t...

Two Ti2AlNb intermetallic orthorhombic (O) alloys, Ti-15Al-33Nb and Ti-21Al29Nb(at.%), were subtransus processed into sheets, using pancake forging and hot-pack rolling, and evaluated in tension (25 and 650°C) and creep (650-710°C) and the properties and deformation behavior were related to microstructure. Some of the microstructural features evaluated were grain boundary character, grain size,...

The time-independent elastic properties of trabecular bone have been extensively investigated, and several stiffness-density relations have been proposed. Although it is recognized that trabecular bone exhibits time-dependent mechanical behaviour, a property of viscoelastic materials, the characterization of this behaviour has received limited attention. The objective of the present study was t...

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...

the creep/recovery behavior of wood flour-polypropylene was compared with medium density fiberboard (mdf) and particleboard. for this purpose, wood flour-polypropylene composites (with and without compatibilizer)were manufactured by using a laboratory twin-screw extruder. the mdf and particleboard panels were obtained from local producers. short term flexural creep tests at 30% of ultimate bend...

the effect of impact modifier on creep behavior of wood flour- recycled polypropylene composites has been evaluated in this work. for this purpose, impact modifier (ethylene vinyl acetate) and recycled polypropylene were mixed with wood flour (50/50% w/w) as well as the impact modifier (0, 3%, 6% and 9%) by a counter-rotating twin-screw extruder to manufacture the wood flour- recycled polypropy...

The objective of these experiments was to test the hypothesis that the "creep currents" induced by Na loading of single frog atrial cells (Hume, J. R., and A. Uehara. 1986. Journal of General Physiology. 87:833) may be generated by an electrogenic Na/Ca exchanger. Creep currents induced by Na loading were examined over a wide range of membrane potentials. During depolarizing voltage-clamp pulse...