五球疲劳试验机接触应力计算方法研究与验证

RESEARCH AND VERIFICATION OF CONTACT STRESS CALCULATION METHOD FOR FIVE-BALL FATIGUE TESTING MACHINE

为对五球疲劳试验机工装接触应力进行精准计算,通过几何尺寸关系确定工装设计接触角,根据载荷变形关系及公式推导,建立外载荷与工作接触角平衡方程,采用迭代法进行求解,计算出受载下工作接触角,进而得到工装的接触应力,最后针对9.525 mm直径被试钢球的工装实际尺寸,分别采用数值算法与有限元方法进行接触应力对比分析,计算结果偏差小于2%,表明接触应力计算数值方法的可靠性,可以快速准确的用于试验方案制定,为试验工装设计提供指导。

To accurately calculate the contact stress of the five-ball fatigue testing machine tooling,the tooling design contact angle is determined by the geometric size relationship.According to the load deformation relationship and the formula derived,the balance equation is established between the external load and the working contact angle.The equation is solved using the iteration method.The working contact angle under load is calculated,and the tooling contact stress is obtained.For the actual size of the 9.525 mm diameter steel ball tooling,the contact stress comparative analysis is calculated by the numerical algorithm and finite element method respectively.The calculation result deviation is less than 2%.It shows the contact stress numerical algorithm is reliable,it can be used for the test protocol formulation and provide guidance for the test tooling design.