We propose a numerical model based on static fatigue laws in order to model the time-dependent damage and deformation of rocks under creep. An empirical relation between time-to-failure and applied stress is used to simulate the behavior of each element of our finite element model. We first review available data on creep experiments, in order to study how the material properties and the loading...

Eyring’s non-linear visco-elastic model has been used to describe two important time dependent mechanical behaviors for textile materials such as stress relaxation and creep. Three yarns suitable for the production of stretch fabrics, viz. 100% wool, wool–lycra and polyester–wool–lycra spun from siro spinning technology are considered in this study. The complex mathematical equations of Eyring’...

We present a nanoindentation study to detect time-dependent deformations in non-polymeric hydrogenated amorphous carbon films. When the bonded hydrogen content increases from 18 to 36 at.%, as measured by Fourier transform infrared spectroscopy, we find that the film becomes less graphitic and softer. Moreover, its hardness shows a larger sensitivity to strain rate and the film with the higher ...

The goal of this study was to develop a nondestructive radial compression technique and to investigate the viscoelastic behavior of the rat tail disc under repeated radial compression. Rat tail intervertebral disc underwent radial compression relaxation testing and creep testing using a custom-made gravitational creep machine. The axisymmetric viscoelasticity and time-dependent recovery were de...

The role of cellulose microfibril orientation in determining cell wall mechanical anisotropy and in the control of the wall plastic versus elastic properties was studied in the adaxial epidermis of onion bulb scales using the constant-load (creep) test. The mean or net cellulose orientation in the outer periclinal wall of the epidermis was parallel to the long axis of the cells. In vitro cell w...

Creep lifetime of turbine blade material subjected to sustained centrifugal forces at elevated temperatures is limited by accumulated inelastic deformation and creep crack growth (CCG). Creep resistance exhibited in conventionally cast polycrystalline (PC) Ni-base superalloy components has been enhanced via solidification techniques. Directional solidification (DS) results in large grain sizes ...

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...

Commercial, aluminum die-cast alloys are subject to long-term stresses leading to viscoelastic material responses resulting in inefficient engine operation and failure. Constant load creep tests were conducted on aluminum die-casting alloys: B-390, eutectic Al-Si and a 17% Si-Al alloys. Rupture occurred in the primary creep regime, with the eutectic alloy having the longest times to failure. Pr...