基于响应面法的热弹流润滑效应下滚动轴承疲劳可靠性分析

Response Surface Method-Based Fatigue Reliability Analysis of Rolling Bearing Considering Thermal Elastohydrodynamic Lubrication Effect

为揭示热弹流润滑效应对滚动轴承疲劳可靠性的影响,采用一种结合二次多项式与一次二阶矩法的响应面法进行分析.考虑弹流润滑效应对温度场的影响,将热应力映射到滚动轴承赫兹接触区内,建立热弹流润滑效应下的滚动轴承接触应力分析模型,同时考虑热弹流润滑效应、材料属性以及疲劳强度修正系数的随机性,结合应力-强度干涉理论,运用所提方法完成热弹流润滑效应下滚动轴承的疲劳可靠性分析.与15万次传统Monte Carlo模拟结果相比,两种计算结果的失效概率之差为2.1×10-4,相对误差为24.4%,而文中所提方法耗时只有Monte Carlo方法的0.15%;随机变量的可靠性灵敏度分析结果符合实际认识,能正确反映热弹流润滑效应对滚动轴承接触疲劳可靠性的影响.

In order to reveal the effects of thermal elastohydrodynamic lubrication （EHL） on the fatigue reliability of rolling bearings, a method combining the response surface method （ RSM ） with the secondary-order polynomial as well as the first-order second moment method （FOSM） is proposed. In the investigation, first, by considering the temperature field influenced by the EHL effect, the thermal stress is mapped into the Hertz contact zone of the rolling bearing, and a model to analyze the contact stress of rolling bearing under the action of thermal EHL is es-tablished. Then, by taking into consideration the thermal EHL effect, the material properties and the randomness of fatigue strength correction factors, the fatigue reliability analysis of rolling bearing under the action of thermal EHL is implemented based on the stress-strength interference theory. As compared with the traditional Monte Carlo meth-od with 1. 5×10^5 simulations, the proposed method gives a difference in failure probability of 2.1×10^4, a rela-tive error of 24. 4% and a relative time consumption of only 0. 15% . Moreover, the sensitivity analysis results agree well with the practical cognition, which means that the proposed method correctly reflects the influence of thermal EHL effect on the contact fatigue reliability of rolling bearings.