Couplage de modèles atomiques et continu, propagation dynamique de fissures

Download or read book Couplage de modèles atomiques et continu, propagation dynamique de fissures written by Pascal Aubertin and published by . This book was released on 2008 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our goal is to link two descriptions, one coming from continuum mechanics, using the X-FEM, the other being atomistic, based on molecular dynamics, in order to describe crack propagation. Using the Cauchy-Born rule, we can establish a link between some classical mechanical quantities and the type of potentiel we use. Thus, within the small displacements assumption, the two models are coherent in a material point of view. We have developped a coupling method, based upon a partition of the mechanical energy. We have sutdied a kinematic coupling enforced via Lagrange multipliers and detailed the energy balance, in the context of explicit dynamics. Finally, we have studied dynamic crack propagation on some 2D examples. The numerical implementation and the techniques that have been used to manage propagation and cracks following are given. Some examples of dynamic failure are shawn and the capabilities of the method are confirmed, particularly for managing crack branching.