In this study, three new strain rate-dependent fracture criteria were proposed and studied upon DP900 steel. The damage threshold was rewritten as a function related to strain rate on the basis of Lou’s fracture theory. Three different uncoupled strain rate base forms were also given: (i) two polynomial forms and (ii) one power form. The model parameters were identified and validated through uniaxial tensile and double bridge shear tests. The prediction accuracies of each model within four different strain rates were compared by contrasting and analysing the experimental and numerical results. In conclusion, the proposed fracture criteria of power form induce the results with the best agreements with experimental ones. These results prove that the proposed fracture criteria can predict ductile failure under different strain rate loadings.

在这项研究中，提出并研究了 DP900 钢的三个新的应变率相关断裂标准。在娄氏断裂理论的基础上，将损伤阈值改写为与应变率相关的函数。还给出了三种不同的非耦合应变率基本形式：（i）两种多项式形式和（ii）一种幂形式。通过单轴拉伸和双桥剪切试验确定和验证模型参数。通过对比和分析实验和数值结果，比较了每种模型在四种不同应变率下的预测精度。总之，所提出的幂形式断裂准则得出的结果与实验结果最吻合。这些结果证明所提出的断裂准则可以预测不同应变率载荷下的延性破坏。