基于损伤力学的凿岩机活塞疲劳寿命仿真研究

发布时间：2018-05-30 20:19

本文选题：活塞 + 疲劳　；参考：《计算机仿真》2017年11期

【摘要】：针对传统的断裂力学无法定量估算液压凿岩机活塞的疲劳裂纹萌生寿命,对冲击活塞运用损伤力学-有限元仿真方法进行疲劳裂纹萌生寿命仿真研究。首先运用Ansys软件对冲击系统进行动力学分析,得出冲击碰撞过程中活塞的应力应变变化规律并确定危险点位置为活塞端面靠近外圆处,随后提取危险点处的应力应变谱响应,结合材料S-N曲线和损伤力学理论,构建损伤演化方程和损伤场与应力应变场的耦合方程,使用损伤力学-有限元方法进行联合仿真,得出活塞疲劳损伤的演化规律呈指数型增长,预估出活塞的疲劳裂纹萌生寿命,给实际生产的活塞设计、制造及热处理工艺等提供了一定的指导,并为评估冲击类构件的疲劳寿命提供了新的分析思路。
[Abstract]:The fatigue crack initiation life of piston of hydraulic rock drill can not be estimated quantitatively by traditional fracture mechanics. The fatigue crack initiation life of impact piston is simulated by using damage mechanics and finite element simulation method. Firstly, the dynamic analysis of the impact system is carried out by using Ansys software, and the law of stress and strain variation of piston during impact is obtained, and the position of danger point is determined as the end face of piston near the outer circle, and then the stress-strain spectrum response of danger point is extracted. Combined with S-N curve and damage mechanics theory, the damage evolution equation and the coupling equation of damage field and stress strain field are constructed, and the damage mechanics finite element method is used to simulate the damage evolution equation. It is concluded that the evolution law of piston fatigue damage is exponentially increasing, and the fatigue crack initiation life of piston is predicted, which provides some guidance for the design, manufacture and heat treatment process of piston produced in practice. It also provides a new analysis method for evaluating the fatigue life of impact components.
【作者单位】：中南大学高性能复杂制造国家重点实验室;
【基金】：国家高技术研究发展计划项目(863计划)(SS2012AA041809) 高性能复杂制造国家重点实验室自主研究课题(zzyjkt2014-08)
【分类号】：TH137.5

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