Accurate prediction of the fracture occurrence of high strength materials is always the hot spot in the research field of metal-forming process. Appropriate material model is the key issue which can accurately describe the mechanical forming behavior under different forming conditions. However, advanced fully coupled damage/behavior models are heavy to use by engineers and have a high cost in term of calculation consuming time. In this paper, a simple uncoupled damage approach, designed to be easy to use for engineers and accurate as well, is investigated. Two uncoupled damage models, which consider the effect of the Lode angle and the hydrostatic pressure, combing three typical hardening rules, are selected and applied to the damage prediction of DP900 dual-phase steel. The hardening properties and forming limit strains under different loading paths of DP900 are investigated and studied throughout a variety of mechanical experiments, including the uniaxial tensile test, the pre-notched tensile tests with three notched radii, and the butterfly tests. Finally, the prediction accuracy of the used models for DP900 is compared and discussed.

中文翻译：

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DP900钢板不同加载路径下两种非耦合延性损伤引发模型的比较

准确预测高强度材料的断裂发生一直是金属成形工艺研究领域的热点。合适的材料模型是准确描述不同成形条件下机械成形行为的关键问题。然而，先进的全耦合损伤/行为模型对于工程师来说使用量很大，并且在计算耗时方面成本很高。在本文中，研究了一种简单的非耦合损坏方法，该方法设计为易于工程师使用且准确无误。选择了两种考虑洛德角和静水压力影响的非耦合损伤模型，结合三种典型的硬化规律，应用于DP900双相钢的损伤预测。DP900 在不同加载路径下的硬化性能和成形极限应变在各种力学实验中进行了研究和研究，包括单轴拉伸试验、具有三个缺口半径的预缺口拉伸试验和蝶形试验。最后，对DP900所用模型的预测精度进行了比较和讨论。