The damage of materials is the progressive or unexpected deterioration of mechanical strength because of loadings, thermal or chemical effects. The micromechanical damage process of ductile materials is generally studied by the continuum damage mechanics (CDM). One of the most well-known damage models is the Lemaitre’s ductile damage criterion. This model only requires one material-dependent parameter to represent damage evolution. In this investigation first, a novel numerical approach is proposed to determine the Lemaitre’s ductile damage parameter. Then, a user-defined material subroutine founded on the Lemaitre’s ductile damage model is developed. Following, numerical results are achieved for a standard round tensile test specimen. Finally, to validate the suggested method, experimental tests are carried out and compared with the numerical results. The comparison reveals a good agreement and excellent correlation between the numerical and practical results. Hence, it is concluded that the offered numerical approach can accurately determine the Lemaitre’s ductile damage parameter as well as the damage behavior of ductile metals.

材料的损坏是由于载荷、热或化学作用导致的机械强度逐渐或意外恶化。延性材料的微观力学损伤过程一般采用连续介质损伤力学（CDM）来研究。最著名的损伤模型之一是 Lemaitre 延性损伤准则。该模型只需要一个与材料相关的参数来表示损伤演化。在这项研究中，首先提出了一种新的数值方法来确定 Lemaitre 的延性损伤参数。然后，开发了基于 Lemaitre 延性损伤模型的用户自定义材料子程序。下面，获得了标准圆形拉伸试样的数值结果。最后，为了验证建议的方法，进行了实验测试并与数值结果进行了比较。比较表明数值和实际结果之间具有良好的一致性和极好的相关性。因此，可以得出结论，所提供的数值方法可以准确地确定 Lemaitre 的延性损伤参数以及延性金属的损伤行为。