We present creep experiments on fiber composite materials. Recorded strain rates and acoustic emission (AE) rates exhibit both a power law relaxation in the primary creep regime and a power-law acceleration before global failure. In particular, we observe time-to-failure power laws in the tertiary regime for acoustic emissions over four decades in time. We also discover correlations between som...

The conditions for localization in a material described by a non-local damage-based constitutive relation coupled with a Kelvin type creep relation are derived in a closed form. The inception of a localized mode is considered as a bifurcation into Preprint submitted to Elsevier Science 15 February 2006 a harmonic mode. The criterion of bifurcation is reduced to the classical form of singularity...

A microstructural model of steady-state creep that couples grain-boundary transport, micromechanics, and grain sliding is employed to investigate the grain-boundary diffusional creep response of an idealized microstructure with variable boundary diffusivities. Both numerical and analytical methods were used to determine the stress state and, in some cases, the strain rate associated with an app...

Determining the dynamic response of frozen soil is important for the study of the deformation, strength and stability of frozen soil under dynamic loading conditions for engineering design in cold regions. This paper discusses the recent progress in research on the dynamic response of frozen soil from the following three aspects: (1) influence of various testing conditions (confining pressure, ...

Low-temperature high-stress rheology of olivine was investigated under water-saturated conditions by large strain shear deformation experiments using the Griggs-type apparatus. Samples at T=1273–1373K and P=2GPa under water-saturated conditions deformed under a significantly lower applied stress than expected from the power-law relation and the strain rate increases more rapidly with stress. Th...

In this paper a rate dependent model for unsaturated geomaterials is presented. The formulation and numerical predictions are compared with available experimental results and discussed. The constitutive laws for the description of the time-dependent mechanical behaviour of saturated and unsaturated geomaterials generalize the isotach approach to the elastoplastic strain hardening based constitu...

Damage evolution during low cycle fatigue, creep, and their interaction behavior is actually a ductility exhaustion process in response to cyclic and static creep. In this article, a novel viscosity-based model for low cycle fatigue creep life prediction is presented in an attempt to condition viscosity-based approaches for general use in isothermal and thermo-mechanical loading. In this model,...

The process of wood drying can induce defects caused by drying stress, which limits the processing and utilization of this valuable material. Here, we investigated elastic strain, viscoelastic creep strain, and mechanosorptive (MS) creep strain caused by shrinkage anisotropy using the image analytical method during slow conventional drying of white birch (Betula platyphylla Suk) disks. The rheo...

The tail tendons from wallabies (Macropus rufogriseus) suffer creep rupture at stresses of 10 MPa or above, whereas their yield stress in a dynamic test is about 144 MPa. At stresses between 20 and 80 MPa, the time-to-rupture decreases exponentially with stress, but at 10 MPa, the lifetime is well above this exponential. For comparison, the stress on a wallaby tail tendon, when its muscle contr...