基于有限元与试验数据的击针疲劳寿命分析

Fatigue life analysis of firing pin based on finite element method and test date

针对击针的疲劳失效问题,以某自动步枪为研究对象,通过有限元仿真对击针进行了应力应变的精确计算,并通过试验验证了有限元模型的正确性。进行了击针材料的力学性能试验与应变寿命试验,得到了击针材料的应力应变数据与疲劳寿命数据;建立击针的有限元模型,仿真分析了其应力应变分布情况;根据击针疲劳数据和有限元分析结果,依据Miner线性累积损伤理论进行了击针的疲劳寿命仿真分析,并进行试验验证。结果表明,击锤在击打击针时,击针最大的Mises应力为击针锥度小端处,最大应力位置与实际断裂位置相吻合;静态响应仿真与实测值误差不超过7%;使用应变寿命曲线计算击针的疲劳寿命与试验疲劳寿命较为吻合。

Aiming at the fatigue failure of the firing pin,an automatic rifle is taken as the research object.The stress and strain of the firing pin are calculated accurately by finite element simulation,the correctness of the finite element model is verified by experiments.The stress-strain data and fatigue life data were derived from the tensile test and strain life test;The finite element model of the firing pin was established and the stress-strain distribution was simulated;Based on the fatigue data and finite element analysis results,the fatigue life simulation of the firing pin was carried out according to Miner’s linear cumulative damage theory,and the experiment was carried out for verification.The results showed that the maximum Mises stress was at the small end of the Mises taper when the hammer struck the firing pin,the maximum stress position is consistent with the actual fracture position;The error between the static response simulation and the measured value is less than 7%;the fatigue life calculated by the strain life curve is in good agreement with the experimental fatigue life.