基于损伤演化的裂纹扩展寿命简化计算方法

Research on calculation method of crack propagation life based on damage evolution

文章结合低周疲劳试验数据,在能量损伤理论、损伤度弹性模量度量法,以及简化的椭圆形裂纹形状扩展模型的基础上提出了一种基于损伤演化的疲劳裂纹扩展寿命简化计算方法。目前疲劳裂纹扩展寿命预测的基础是基于断裂力学的Paris公式,鉴于基于应变—寿命曲线的疲劳损伤演化与基于断裂力学的裂纹扩展本质上的一致性,文章提出的简化计算方法不但具有明确的物理意义,也对评估裂纹扩展寿命提出了一种基于损伤力学的新视角。同时,文中也对某船用高强度钢进行了算例计算和分析。结果表明,该方法计算过程便捷,在船舶工程结构寿命评估方面存在一定的实用价值。

A simplified calculation method of crack propagation life（CPL） based on damage evolution was presented by studying on the theory of energy damage and fatigue damage in elasticity modulus and the simplified expanding model of the elliptic crack. The calculation of CPL by building on Paris formula based on fracture mechanics was the foundation method for the moment. The conception of the method in this paper was clear and novel because of the essence of fatigue damage based on Δε-Ν curve and Paris formula was coincident. The results of the example show that the method of this paper was valuable to the evaluation of the ship structure fatigue life.