刨煤机牵引块可靠性分析及疲劳寿命预测

Plow traction block reliability analysis and fatigue life prediction

以刚柔耦合多体动力学基本理论及疲劳寿命预测理论及方法为基础,建立刨煤机刚柔耦合虚拟样机模型,解决了仿真动态载荷获取、载荷施加位置及方式的确定和柔性牵引块接触面刚化处理等问题。对样机进行仿真,分析得出整机设计上存在的问题。对牵引块两端斜面角度及耳部尺寸进行优化,加工方法由铸造改为模锻,使其应力特性基本满足设计要求。对牵引块疲劳破坏危险部位关键节点主应力载荷进行强化外推及多工况叠加处理,得到用于疲劳分析的目标载荷谱。进行节点疲劳寿命预测,得到牵引块较为准确的疲劳寿命。

Based on basic theory of rigid-flex coupled multi-body dynamics and the theory and method of fatigue life prediction,a rigid-flex coupled virtual prototyping model of coal plough was built;the problems of simulation dynamic load acquisition,the place and method of loading,interface rigidization processing of flexible traction block were solved.Through the analysis of prototype simulation,design problems of the whole coal plough were obtained.Optimized the cant angles and ear sizes of both ends of the traction block,changed the processing method from casting to forging,and then the stress characteristics could basically meet the design requirements.Strengthening extrapolating and superposition working processing was taken on the key points＇ Von Mises of dangerous fatigue damage areas,target load spectrum of fatigue analysis was obtained.Through Node fatigue life prediction,relatively accurate fatigue life of the traction block was obtained.