The purpose of this article is to model defect nucleation. The defect is considered as a small volume which evolves as a damaged zone. The damage is described by a transition zone which can be sharp or continuous. In the first case, discontinuities occur and the initiation of defect is based on bifurcation of an equilibrium state. When the transition is continuous, the initiation of the defect is continuous.The analysis is based on considering different models of damage, depending on the regularity imposed on mechanical field. For each model, the presence of discontinuities on mechanical fields is investigated. Consequences of each model on defect nucleation are illustrated on particular structures: bars under extension and spheres under radial loading.

本文的目的是对缺陷成核进行建模。缺陷被认为是一个小体积，它演变为一个损坏区域。损坏由过渡区描述，过渡区可以是尖锐的或连续的。在第一种情况下，会出现不连续性，缺陷的产生是基于平衡状态的分叉。当过渡是连续的时，缺陷的产生是连续的。分析是基于考虑不同的损伤模型，取决于施加在机械场上的规律性。对于每个模型，研究了机械场上不连续性的存在。每个模型对缺陷成核的后果在特定结构上进行了说明：拉伸下的棒和径向载荷下的球。