自行火炮行动系统关重件的疲劳寿命仿真

建立了某型自行火炮虚拟样机模型，仿真并获得了各典型行驶工况下行动系统关重件的载荷时间历程。以扭力轴为研究对象，对各单一工况下的二维随机扭矩载荷进行计数统计和分布检验，采用权系数法、概率密度推断法和最速下降法对载荷进行多工况的合成和扩展，获得了其全寿命里程二维设计谱。并通过有限元分析和名义应力法，运用MM( modified miner)法则和EM( elemental miner)法则对扭力轴进行材料疲劳特性修正和安全寿命预测，结果表明：MM法则更为合理一些，并认为扭力轴不萌生宏观裂纹的疲劳寿命为12 814 km．

Fatigue Life Simulation of Key Components of Running Gear for a Self-propelled Gun

The virtual prototype of the self-propelled gun was established,the load of the key components of running system under various driving conditions was simulated and obtained.For a single condition,stochastic load acting on the torsion bar was simulated,counted,evaluated and tested to obtain a distribution form. Using the weight coefficient method,the probability density deducing method and the steepest descent method,the fatigue load on various conditions was synthesized and extended. Moreover,two-dimensional design spectrum of the whole lives was established.The fatigue parameters of the torsion bar's material were modified with modified miner(MM) rule and elemental miner(EM) rule.Utilizing the nominal stress method,the torsion bar's fatigue safe lives were predicted.As a result,it is not probable to propagate fatigue cracks for the torsion bar within 12 814 km.And it shows that MM is more reasonable than EM.