Modelling deformation and failure of materials under dynamic loading conditions

摘要

Modelling deformation and failure of materials under dynamic loading conditions. There is an increasing demand for thermomechanical computations of structures under dynamic loading conditions for which the current methods are often unsatisfactory. A simple analysis quickly shows that different dynamic regimes can be distinguished depending on the magnitude of inertia effects. Furthermore, it is shown that the space scaling becomes time dependent. Experimental, theoretical and numerical tools are still evolving and have not yet reached a sufficient degree of maturity. This is due to the inherent complexity of dynamic problems such as wave propagation, heating and thermomechanical coupling, rate-dependent phenomenology, space and time dependent characteristic scales. An overview of the current knowledge allows one to identify missing developments in experiments, constitutive models including degradation and failure effects, as well as computational strategies. It is shown that the state of the art is very disparate when considering different material classes such as polymers, composites and foams for which few studies are conducted. For metals, concrete, ceramics and glasses some results are available but more advanced studies are still needed. Some future directions of research are sketched and they constitute the scope of the newly created working group common to the MECAMAT and DYMAT societies, both members of the French Society of Mechanics. Its first meeting was held April 4-5, 2000, in Poitiers.