Showing papers by "Vadim V. Silberschmidt published in 1998"
Journal Article•
TL;DR: A well-positioned CDM model and an adequate representation of deterministic and random inhomogeneity factors, combined with an efficient numerical algorithm of modified lattices, yield a realistic simulation of the rupture properties of alumina ceramic specimens at tensile tests as discussed by the authors.
Abstract: A WELL-POSED CDM model and an adequate representation of deterministic and random inhomogeneity factors, combined with an efficient numerical algorithm of modified lattices, yield a realistic simulation of the rupture properties of alumina ceramic specimens at tensile tests. Effects of energy dissipation and acoustic emission, the load-carrying capacity and the post-critical response are analysed in dependence of the heterogeneity realisations, which are related to the initial damage distribution within the specimen. This distribution is shown to be a crucial factor determining the response of brittle damaging ceramics at rupture.
8 citations
TL;DR: In this article, the inhomogeneity of material properties is modelled in terms of an initial damage distribution in the specimen's cross section, which reflects both the radial porosity variation in sintered specimens and the randomness of the structural fluctuations in the circumferenial direction.
7 citations
TL;DR: In this paper, a kinetic equation of damage evolution for stochastic conditions is proposed and a local failure criterion via a threshold damage concentration is introduced to analyze the time-to-fracture distributions and their change with the noise intensity.
Abstract: Characteristic features of damage accumulation under arbitrary stochastic conditions are studied in terms of continuum damage mechanics (CDM). A uniaxial tension case is chosen for a simplicity of discussion and clearness of results' interpretations. Modification for a kinetic equation of damage evolution for stochastic conditions is proposed. Numerical algorithms for three types of stochasticity—(a) additional noise (fluctuations in external load), (b) inner noise (as result of the non-uniform evolution of ensembles of micro-defects) and (c) combination of previous two factors—are obtained. Introduction of a local failure criterion via a threshold damage concentration allows the time-to-fracture distributions and their change with the noise intensity to be analyzed.
6 citations
TL;DR: In this paper, a new quantitative method for the analysis of matrix cracking in 0 m /90 n s carbon-epoxy cross-ply laminates under cyclic loading is suggested on the basis of fractal theory.
5 citations
TL;DR: In this paper, the effects of a nanosecond laser pulse in plates of Armco-iron are analyzed and the localisation of processes of martensitic transformation and twinning is studied both experimentally and numerically.
Abstract: Effects of shock waves (generated by a nanosecond laser pulse in plates of Armco-iron) on structural changes are analysed. Localisation of processes of martensitic transformation and twinning – for various values of laser pulse duration – is studied both experimentally and numerically. A proposed model accounts for interaction of shock wave propagation and structure changes. Realisation of martensitic transformation and twin formation influences wave front modification. A stress amplitude decrease with increasing distance from a microcrater determines, together with the pulse duration, a character of spatial localisation of structural changes. Numerical results are compared with experimental data and serve as a basis for additional interpretation of phenomena.
3 citations
TL;DR: In this paper, the authors studied the effect of initial damage on failure development under constant stress and the existence of two threshold stresses is linked with the presence of three various stress intervals and respective regimes of damage growth.
Abstract: Shear damage development under constant stress is studied on the basis of the analytical solution of kinetic equations of damage accumulation. The existence of two threshold stresses is linked with the presence of three various stress intervals and respective regimes of damage growth. Utilization of the limit value of damage level as the failure criterion allows the scaling of the time-to-failure to be analyzed. The effect of initial damage on failure development is investigated.