Abstract This paper presents an elastoplastic/damage model that couples the constitutive equations of the extended subloading surface plasticity theory with a scalar isotropic ductile damage variable in the continuum damage mechanics framework. The model has previously been applied to Q460 construction steel bars and plates but has not been considered for application to SM steels, which are particularly used in welded structures. The Mohr–Coulomb (MC) fracture criterion was adopted to describe the damage evolution in SM490Y carbon steel. This criterion has been successfully applied to rock and soil mechanics because it can consider the effect of the hydrostatic pressure and Lode angle parameter, which are particularly relevant for this type of material. These two parameters also control the failure of metallic materials, so the field of application for the MC criterion can be extended. Experimental tests were carried out on notched bars and flat grooved plates under monotonic extension to characterize the fracture surface under different values of the stress triaxiality and Lode angle parameter. The results were used to calibrate and validate the numerical model's ability to describe ductile damage.

中文翻译：

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焊接结构用碳钢的韧性行为：实验和数值模拟

摘要 本文提出了一种弹塑性/损伤模型，该模型将扩展子加载表面塑性理论的本构方程与连续损伤力学框架中的标量各向同性延性损伤变量耦合。该模型之前已应用于 Q460 建筑钢筋和钢板，但尚未考虑应用于 SM 钢，特别用于焊接结构。采用 Mohr-Coulomb (MC) 断裂准则来描述 SM490Y 碳钢的损伤演变。该准则已成功应用于岩土力学，因为它可以考虑静水压力和洛德角参数的影响，这与此类材料特别相关。这两个参数也控制着金属材料的失效，因此可以扩展 MC 准则的应用领域。在单调拉伸条件下对缺口杆和平槽板进行了实验测试，以表征不同应力三轴度和洛德角参数值下的断裂面。结果用于校准和验证数值模型描述延性损伤的能力。