Abstract: Reasonable design and selection of automobile tansmission shaft is very important to ensure the reliability of vehicle power system. Considering the influence of safety factor, the reliability mathematical model of the stress limit state of the transmission shaft is established, and the reliability design theory, first order second moment method (FSOM) and Monte-Carlo simulation (MCS) numerical simulation method are combined to calculate the structural reliability and reliability sensitivity of automobile transmission shaft. Taking a certain type of automobile transmission shaft as an example, the reliability of automobile transmission shaft selection under the influence of safety factor is discussed. The most influential factors of automobile transmission shaft reliability are obtained, which provides an important reference value for the subsequent structural selection and steady optimization design of the automobile transmission shaft.

Key words: automobile transmission shaft; safety factor; strength; structural reliability; reliability sensitivity

摘要： 合理地设计和选用汽车传动轴对保证整车动力系统可靠性非常重要。考虑安全系数的 影响，建立传动轴应力极限状态的可靠性数模，将可靠性设计理论、一次二阶矩方法（FSOM） 和 Monte-Carlo 仿真（MCS）数值模拟法相结合，计算了结构可靠度和可靠性灵敏度。以某 型汽车传动轴为算例，讨论汽车传动轴在安全系数影响下选用的可靠性，得到了汽车传动轴 结构可靠性最大的影响因素，为汽车传动轴后续的结构选型及稳健优化设计提供了重要的参 考价值。

关键词: 汽车传动轴；安全系数；强度；结构可靠度；可靠性灵敏度