The creep behavior of bagasse-based composites with virgin and recycled polyvinyl chloride (B/PVC) and high density polyethylene (B/HDPE) as well as a commercial wood and HDPE composite decking material was investigated. The instantaneous deformation and creep rate of all composites at the same loading level increased at higher temperatures. At a constant load level, B/PVC composites had better...

Long term tensile creep studies were conducted on binary NiAl in the temperature range 700-1200 K with the objectives of characterizing and understanding the creep mechanisms. Inverse and normal primary creep curves were observed depending on stress and temperature. It is concluded that the primary creep of NiAl is limited by dislocation mobility. The stress exponent for creep, n, decreased fro...

Polypropylene is one of the most common, fastest growing and versatile thermoplastics currently used to produce tanks and chemical piping systems. Even at room temperature creep is considerable for polypropylene products. The creep behavior of strains, stresses, and displacement rates is investigated in a thick-walled cylinder made of polypropylene reinforced by functionally graded (FG) multi-w...

This study was conducted with grazing nursing calves (197 kg) to determine the effects of 1) limiting creep feed intake and 2) increasing the concentration of ruminal escape CP in creep feed at a limited level of creep feed intake on fescue and milk intake, ruminal NDF digestion, and total tract digestibility in calves fed high-quality, freshly harvested fescue. The treatments were 1) control (...

The inverse problem of determining the unknown coefficient of the non-linear differential equation of torsional creep is studied. The unknown coefficient g = g(ξ2) depends on the gradient ξ := |∇u| of the solution u(x), x ∈ Ω ⊂ Rn , of the direct problem. It is proved that this gradient is bounded in C-norm. This permits one to choose the natural class of admissible coefficients for the conside...

We studied the elastic moduli, ductile creep behavior, and brittle strength of shale-gas reservoir rocks from Barnett, Haynesville, Eagle Ford, and Fort St. John shale in a series of triaxial laboratory experiments. We found a strong correlation between the shale compositions, in particular, the volume of clay plus kerogen and intact rock strength, frictional strength, and viscoplastic creep. V...

Macroscopic slip velocity, macroscopic temperature jump, thermal creep velocity and diffusion slip velocity for a mixture of monatomic gases are calculated by using a method developed recently (modified Maxwell-method) for a general gas-gas and gas-surface interaction law, and for a possibly anisotropic surface. The results are expressed in terms of accommodation coefficients of first and secon...

Indentation creep tests and finite element simulations were performed on a model material to show that the constitutive equation for conventional uniaxial creep can be derived using the instrumented indentation testing technique. When the indentation pressure and the indentation creep rate are maintained at constant values of ps and _ 3⁄4inðsÞ, respectively, the contours of the equivalent stres...

Background—Creep-fatigue behavior is identified as the incorporated effects of fatigue and creep. One class of constitutive-based models attempts to evaluate creep and fatigue separately, but the interaction of fatigue and creep is neglected. Other models treat the damage as a single component, but the complex numerical structures that result are inconvenient for engineering application. The mo...

Gamma titanium aluminides (γ-TiAl) display significantly improved high temperature mechanical properties over conventional titanium alloys. Due to their low densities, these alloys are increasingly becoming strong candidates to replace nickel-base superalloys in future gas turbine aeroengine components. To determine the safe operating life of such components, a good understanding of their creep...