竞争失效场合加速试验(AT)技术是加速试验由简单结构产品向复杂结构产品推广应用的基础。但目前的方法主要针对恒定应力加速试验,而对竞争失效场合步进应力加速试验缺乏相关研究。针对这一问题,对最一般形式(突发型失效和退化型失效并存)的竞争失效场合步进应力试验进行建模与分析。充分考虑了试验数据由于试验截尾和失效样本对应的失效模式不确定而产生的非完整性,在此基础上分别采用基于期望最大化(EM)算法的极大似然估计(MLE)和伪失效寿命MLE,对突发型失效模式和退化型失效模式进行统计分析。最后应用实例验证了方法的有效性。 Competitive failure occasion Accelerated test (AT) technology is the basis for accelerating the application of simple structure products to complex structure products. However, the current methods mainly focus on the constant stress acceleration test, but there is no relevant research on the step stress acceleration test on the occasion of the competitive failure. In response to this problem, the most general form (sudden failure and degenerative failure coexist) competition failure occasional step stress test modeling and analysis. The incompleteness of the experimental data due to the uncertainty of the failure modes of the experimental censored and the failed samples is fully considered. Based on this, maximum likelihood estimation (MLE) based on expectation maximization (EM) algorithm and pseudo- Failure life MLE, the burst failure mode and degenerative failure mode for statistical analysis. The final application example verifies the effectiveness of the method.