A thermomechanical fatigue life prediction model based on the theory of damage mechanics is presented. The damage evolution, corresponding to the material degradation under cyclic thermomechanical loading, is quantified thermodynamic framework. The damage, as an internal state variable, is coupled with unified viscoplastic constitutive model to characterize the response of solder alloys. The da...

Firstand second-order asymptotic solutions are given for the problem of a Mode I crack rapidly propagating in an elastic}viscoplastic solid. Results are obtained for the order of the crack-tip singularity, the angular position at which unloading occurs, and the angular variations of stresses and velocities. It is shown that the eigenvalue, which determines the order of stress singularity, relat...

A method using experimental nanoindentation and inverse finite-element analysis (FEA) has been developed that enables the spatial variation of material constitutive properties to be accurately determined. The method was used to measure property variation in a three-dimensional printed (3DP) polymeric material. The accuracy of the method is dependent on the applicability of the constitutive mode...

The objective of this review is to examine how the concept of plasticity is used in geophysical fluid dynamics. Rapid mass movements such s snow avalanches or debris flows involve slurries of solid particles (ice, boulder, clay, etc.) within an interstitial fluid (air, water). The bulk ehavior of these materials has often been modeled as plastic materials, i.e., a plastic material yields and st...

In this companion article, we present within the finite element context the numerical algorithms for the integration of the thermodynamically consistent formulation of geometrically nonlinear gradient-enhanced viscoinelasticity derived in the first part of the article. The proposed unified integration algorithms are extensions of the classical rate-independent return mapping algorithms to the r...

The finite element method is the reference technique in the simulation of metal forming and provides excellent results with both Eulerian and Lagrangian implementations. The latter approach is more natural and direct but the large deformations involved in such processes require remeshing-rezoning algorithms that increase the computational times and reduce the quality of the results. Meshfree me...

The viscoplastic behavior of polycrystalline Mg 2 SiO 4 wadsleyite aggregates, a major high pressure phase the mantle transition zone Earth (depth range: 410–520 km), is obtained by properly bridging several scale models. At very fine nanometric corresponding to dislocation core structure, thermally activated plastic slip modeled for strain-rates relevant laboratory experimental conditions, at ...

Many problems in engineering and geophysics feature the free surface flow of a viscoplastic fluid. Although negligible at large scales (e.g. lava flows landslides), capillary forces may become significant small coating polymeric materials 3D printing). The effect yield stress on spreading droplets is considered. Experiments, asymptotic solutions, numerical simulations are used to explain drople...