LY12螺栓孔裂纹失效分析

Analysis on Crack Failure of LY12 Bolt Hole

针对机械弯臂结构螺栓孔裂纹问题,利用有限元分析方式对其受载进行分析,并通过成分分析、硬度检测、宏观分析和显微分析等方法,对其裂纹产生的原因进行深入研究,结果表明,铝合金表面的防护漆层遭到破坏后暴露出来的金属,在与装配件的摩擦过程中形成早期裂纹源,而由于组织内的位错密度较低,在长期循环载荷作用下,早期裂纹源极易扩展造成最终的钛合金断裂失效。

Concerning crack failure of bolt hole for mechanical curved arm,strength load is analyzed by adopting the finite element method and in-depth study on the cause of crack is conducted through composition analysis,hardness testing,macroscopic observation and microscopic observation. The result suggests that the early source of crack is induced during the friction between the exposed metal when the protection layer of Al alloy surface is damaged and the assembly parts. As the dislocation density inside the organization is low,the early source of crack can be easily extended to fracture of titanium alloy ultimately under the effect of long-term cyclic loading.