为研究微动对搭接结构疲劳寿命的影响,采用ABAQUS软件建立了考虑微动影响的单搭接结构有限元全局模型和子模型,运用该模型计算了接触区的应力分布。并在FRANC2D/L中把螺栓用等效的正应力和剪应力来代替,重建子模型,计算了裂纹尖端应力强度因子。最后建立了考虑微动影响下的搭接结构疲劳寿命预测模型,并将计算值与试验值进行了对比。结果表明,微动对搭接结构有较大的影响,它可以较大幅度地降低搭接件的疲劳寿命;考虑微动时的预测精度高于不考虑微动时的预测精度,且直孔搭接件的预测精度明显高于沉孔搭接件。
A global finite element model and sub-model of single lap joint considering fretting was performed using the commercial code ABAQUS to study the influence of fretting on fatigue life of lap joint. Distribution rules of contacting stress were calculated using this model. The sub-model with the fracture mechanics code FRANC2D/L was reconstructed by substituting bolts with their equivalent loads of normal and shear tractions. Also stress intensity factors along crack lengths were calculated. At last the fatigue life prediction model for single lap joint considering fretting was established, and the experimental data was compared to the computing results. The results showed that fretting has a great effect on the fatigue life of single lap joint. The prediction precision considering fretting is better than the unconsidering one; also the prediction precision of straight hole is better than that of the countersunk clearly.