Mines ParisTech

About: Mines ParisTech is a education organization based out in Paris, France. It is known for research contribution in the topics: Finite element method & Microstructure. The organization has 6564 authors who have published 11676 publications receiving 359898 citations. The organization is also known as: École nationale supérieure des mines de Paris & École des mines de Paris.

An enhanced Lemaitre model formulation for materials processing damage computation

Abstract: The Lemaitre damage model is now widely used to deal with coupled damage analyses for various mechanical applications. In this article, different extensions of the model are presented and discussed to deal with complex multiaxial configurations—such as multi-stages bulk forming processes. A specific treatment is done to account for compressive damage growth, and a stress triaxiality cut-off value is considered to avoid any damage evolution below a critical negative triaxiality. The damage potential is also modified to deal with highly ductile materials, and the plastic strain is split into a negative part and a positive part to differentiate damage growth for compressive states of stress and for tensile states of stress. Finally, an anisotropic damage approach based on the comparison between grain flow orientation and principal loading directions is defined. A combination of these extensions is achieved within a single Lemaitre formulation. Application on different examples show the robustness and accuracy of the model defined in this paper.

Linear system theory for discrete event systems

Abstract: In this paper, we pursue the Analogy between classical linear System Theory and a new "linear" Theory for Discrete-Event Dynamic Systems which has been introduced for the first time in [3] and which is based on the algebra of "dioids". We first define the particular class of timed Petri nets that can be described by "linear" recurrent equations and then develop concepts such as transfer matrix representations of such systems, stability, observability, controllability, feed-back stabilization, realization of transfer matrices etc...