A study on Crack propagation characteristics of interlaced holes for key automotive components.

Aiming at the engineering problem that the stress interference of interlaced holes dominates crack propagation and directly affects driving safety in the hole group structure of key components such as chassis and body frame in the automotive field, in order to accurately reveal the quantitative influence of key parameters of interlaced hole placement (crack deflection Angle, longitudinal hole spacing) on the crack evolution of automotive hole group components, This study adopts the approach of numerical simulation combined with variable control to conduct systematic analysis. Taking an aluminum alloy thin plate with two relatively initial cracks (a commonly used structural material for automobiles) as the research object, multiple sets of typical interlocking hole structure variable models of automotive components covering different crack deflection angles and longitudinal hole spacings were constructed in the ABAQUS software. The J-integral was calculated by the circumscribed line integration method and converted into the stress intensity factor. Accurately predict the crack propagation path by combining the maximum circumferential stress criterion. The results show that the initial cracks deflecting towards each other, regardless of the magnitude of the initial deflection Angle, eventually tend to propagate in the horizontal direction. The initial cracks with opposite deflection are prone to produce significant interference effects, and the smaller the deflection Angle, the more prominent the interference phenomenon. Comparative analysis reveals that the influence of interlaced holes on the crack propagation trajectory is much less than that of the interaction between cracks. This research can provide more accurate quantitative references for crack prevention, risk control and safety design optimization of hole group structures such as automotive chassis and body frames.