弹塑性裂纹前端部分加强板的止裂效果分析

通过建立Dugdale模型,对裂纹前端部分加强的含裂纹板弹塑性情况下的韧性断裂问题进行了研究.实例计算并分析了加强板条的位置、相对刚度等参数对结构断裂参数的影响,亦对加强板条的止裂作用进行了分析.计算结果表明,裂纹前端布置加强板条能有效地降低裂纹尖端的开口位移,阻止裂纹的扩展,其止裂作用受加强板条的位置、结构参数及加强板条与含裂纹板的材料参数等诸多因素的影响.

Ductile Fracture Analysis on the Crack Arrest Effect of the Crack Front Reinforcement

This paper presents a solution to the ductile fracture problem of cracked plate locally reinforced near the crack front subjected to remote normal stress. The rigidity of the stiffener in the transverse direction is neglected. It is assumed that the shear stress which develops at the interface between the plate and reinforcement is constant along its thickness and its width. The shear stress is considered to be lumped at a finite number of locations. Considering the compatibility condition at these load locations, the Dugdale solutions for the plastic zone size and CTOD (Crack Tip Opening Displacement) are derived. A parametric study involving the stiffener location, stiffener relative stiffness is carried out. The numerical results show that the CTOD depends on all these factors. There is a location of the stiffener which is the most advantageous. The reinforcement effect becomes better as the stiffener relative stiffness is larger. These results are of practical importance in the fail-safe design of structures.