基于疲劳寿命计算的拉杆螺纹联接结构优化设计

摘要

高频次工作的液压机机架中,拉杆螺纹联接处的疲劳断裂是机架失效的主要原因.在考虑材料弹塑性接触的基础上,对拉杆螺纹联接结构进行参数化有限元仿真分析,根据分析结果,选择Brown-Miller算法对螺纹联接进行疲劳寿命计算,研究不同过渡圆弧半径和牙侧角对螺纹联接疲劳寿命的影响规律并对其参数进行优化.结果表明:优化后螺纹联接的疲劳寿命提高了51.71％,不均匀系数减少了48.38％,最大等效VonMises应力减少了4.93％,第一主应力减少了8.64％.%In the high frequency hydraulic frame,the fatigue fracture of the rod is the main cause of the failure of the frame.On the basis of considering the elastic plastic contact of the material,it carries out the finite element simulation analysis on the connection structure of the rod thread,then takes Brown-Miller algorithm to calculate the fatigue life of screw connection.It analyzes the effects of the different transitional radius and flank angle on fatigue life,optimizes the parameters.The results show that the optimization method increases fatigue life 51.71％,reduces the non-uniform rate of load distribution 48.38％ and the maximum equivalent VonMises stress 4.93％,and also reduces the first principal stress 8.64％.