平面状态对疲劳裂纹数值扩展的影响研究

Influence of Plane State on Numerical Propagation of Fatigue Crack

为了研究不同的平面状态对疲劳裂纹数值扩展的影响,将权重系数用于平面内任意位置的应力强度因子表达式,然后基于提出的相对深度系数的概念,假设了3种权重系数与相对深度系数的关系。通过3种关系下的应力强度因子表达式,进行3种关系下的疲劳裂纹数值扩展,并利用所提出的数值结果处理方法得到3种关系下的数值扩展精度。结果表明,当平面状态为平面应力状态与平面应变状态的组合状态、且权重系数与相对深度系数关系为二次函数时,数值扩展结果最好。

In order to study the influence of different plane states on fatigue crack numerical propagation,the weight coefficients were applied to the expressions of stress intensity factors at any position in the plane.Then,based on the proposed concept of relative depth coefficients,the relationships between three weight coefficients and relative depth coefficients were assumed.The numerical propagation of fatigue cracks under three kinds of relations is carried out by using the expressions of stress intensity factors under three kinds of relations,and the numerical propagation accuracy under three kinds of relations is obtained by using the numerical result processing method proposed in this paper.The results show that when the plane state is a combination of plane stress state and plane strain state,and the relation between weight coefficient and relative depth coefficient is a quadratic function,the numerical extension result is the best.