The paper deals with the effect of different stress-state-dependent damage mechanisms on the onset of fracture in ductile metals. A continuum damage model is discussed using a strain tensor as an appropriate damage variable. It takes into account the influence of stress state on the damage condition and on the evolution equations of damage strains. A fracture condition based on critical damage parameters is developed analyzing results of a series of new experiments with different biaxially loaded specimens. After the tests, fracture modes are visualized by scanning electron microscopy. Numerical simulations of the biaxial experiments elucidate the stress states in critical regions of the specimens which are used to explain formation of different damage and fracture modes on the micro-level. Analysis of numerically predicted damage strains for different loading cases leads to a generalized fracture criterion.

本文探讨了不同的应力状态相关的损伤机制对延性金属断裂开始的影响。使用应变张量作为适当的损伤变量讨论了连续损伤模型。它考虑了应力状态对损伤条件和损伤应变演化方程的影响。基于临界损伤参数的断裂条件被开发出来，分析了一系列使用不同双轴载荷试样的新实验的结果。测试后，通过扫描电子显微镜观察断裂模式。双轴实验的数值模拟阐明了样品关键区域的应力状态，这些应力状态用于解释微观水平上不同损伤和断裂模式的形成。