低周疲劳随机损伤过程的有限元模拟

讨论了一种低周疲劳下随机损伤演变过程 数值模拟方法，借助于Ｌｅｍａｉｔｒｅ＆Ｄｕｆａｉｌｌｙ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的的微缺陷，将所得模型与有限元结合对低周疲劳损伤过程进行了数值模拟。

SIMULATION OF THE STOCHASTIC DAMAGE EVOLUTIONPROCESS UNDER LOW CYCLE FATIGUE BY THE FINITE ELEMENT METHOD

A numerical simulation of stochastic damage evolution process in the condition of1ow cycle fatigue loading is discussed. The relations between damage variables and micro-cracks areobtained by means of the micro-mechanics model of the representative volume element proposed byLemaitre and Dufailly10]. The stochastic initial damage values are introduced in consideration of theinherent micro-defects in materials. The model combined with a finite element method is applied tosimulate the damage evolution process under low cycle fatigue 1oading-The micro-cracks on the surface of a specimen of 19Mn6 al1oy steel are measured with a replica technique. The numerical results show that the nonhomogeneity of damage and the localization of the fatigue failure are wellshown by the proposed simulations, and the fatigue lives are reasonably predicted.