振打机构摆臂疲劳寿命仿真及可靠性分析

目的 针对振打机构关键部件摆臂,开展疲劳寿命及关键参数影响程度仿真分析,获得寿命分布及可靠性数据,校核摆臂设计是否满足使用要求。方法 基于S-N曲线进行振打机构摆臂的寿命仿真,开展动力学仿真与应力仿真,获得不同温度下摆臂最低寿命与管壁壁厚的关系。通过对关键寿命影响参数进行影响程度仿真分析,获得寿命分布及可靠性数据。结果 当摆臂壁厚大于1.77mm时,摆臂的平均寿命大于144万次,满足产品设计要求。疲劳寿命与弹性模量E负相关,与抗拉强度和表面加工系数正相关。可靠度R取0.8时,摆臂的可靠寿命约为29 005次;可靠度R取0.9时,摆臂的可靠寿命约为11 891次。结论 振打机构摆臂壁厚需大于1.77 mm,摆臂表面质量系数大于0.827 3,材质抗拉强度大于907.76 MPa,弹性模量E小于2.041×10^(5)MPa。

Fatigue Life Simulation and Reliability Analysis of Rapping Mechanism Swing Arm

The work aims to conduct simulation analysis of the fatigue life and the effect degree of key parameters for the swing arm of the rapping mechanism to obtain life distribution and reliability data of the swing arm, so as to check whether the design of the swing arm meets the requirements of use. The life simulation of the swing arm of the rapping mechanism was carried out based on the S-N curve. Dynamic simulation and stress simulation were carried out to obtain the relationship between the minimum life and the wall thickness of the swing arm at different temperature. Through simulation analysis on the effect degree of key parameters of life, life distribution and reliability data were obtained. When the wall thickness of the swing arm was greater than 1.77 mm, the average life of the swing arm was more than 1.44 million times, which met the product design requirements. Fatigue life was negatively correlated with elastic modulus E and positively correlated with tensile strength and surface finish coefficient. When the reliability R was 0.8, the reliable life of the swing arm was about 29 005 times; when the reliability R was 0.9, the reliable life of the swing arm was about 11 891 times. The wall thickness of the swing arm of the rapping mechanism should be greater than 1.77 mm. The surface quality coefficient of the swing arm should be greater than 0.827 3, the tensile strength of the material should be greater than 907.76 MPa, and the elastic modulus E should be less than 2.041×105 MPa.