论文部分内容阅读
讨论一种低周疲劳下随机损伤演变过程的数值模拟方法．借助于Lemaitre＆Du－faillv［10］给出的代表性体元的微观力学模型，建立了损伤与微裂纹尺寸的关系．采用随机初始损伤反映材料中固有的微缺陷，将所得模型与有限元法结合对低周疲劳损伤过程进行了数值模拟．采用复膜技术对低周疲劳下的19Mn6合金钢试件的表面微裂纹进行跟踪量测以供对照．数值结果表明，采用该方法能反映材料损伤的非均匀发展和疲劳失效的局部性，并给出合理的疲劳寿命预测结果．
A numerical simulation method of random damage evolution under low cycle fatigue is discussed. With the help of the micro-mechanical model of the representative voxels given by Lemaitre & Du-faillv [10], the relationship between the damage and the size of the microcracks was established. The random initial damage is used to reflect the micro-defects inherent in the material, and the finite element method is used to simulate the low-cycle fatigue damage process. Friction technique was used to measure the surface microcracks of 19Mn6 alloy specimens under low cycle fatigue for comparison. Numerical results show that this method can reflect the non-uniform development of material damage and the fatigue failure of the locality, and gives a reasonable prediction of fatigue life.