汽车副车架安装螺栓碰撞断裂的数值模拟研究

Numerical Simulation on Mounted Bolt Failures in Vehicle Subframe

针对10.9级M14高强螺栓碰撞断裂,设计了三种不同受力状态的螺栓强度试验,采用有限元逆向参数方法获得不同应力三轴度下的断裂极限应变,建立了螺栓材料的CrachFEM剪切断裂模型。基于副车架总成试验的数值模拟研究了变直径螺栓的抗剪切强度,为考虑碰撞要求的设计提供了可靠的模拟方法,同时也表明CrachFEM模型能够很好地预测高强螺栓的断裂失效行为。

A high-strength mounted bolt(10.9, M14)was taken as the research object, 3 bolt strength tests were designed for different loading status. The fracture strain under different stresses triaxiality was calibrated using finite element simulation and parameter reverse methods and CrachFEM shear failure model was constructed for bolt material. The shear fracture strength was studied for variable diameters of mounted bolt during tests and simulation for subframe, and it provides the stable simulation method for mounted bolt design for subframe to satisfy the crash requirements. The correlation work also demonstrates that CrachFEM model may better predict the fracture failure behavior of high-strength mounted bolts.