步降应力加速寿命试验（续篇)-一-优化设计篇

如何设计试验方案使试验评估结果最准确、试验代价最小，是步降应力加速寿命试验应用中面临的一个重要问题。针对传统解析优化方法在某些场合最优解的封闭形式难以得到甚至不存在的情况，提出了一种新的基于Monte Carlo仿真的步降应力加速寿命试验优化设计方法，并且针对Monte Carlo方法高精度计算中的计算量问题，利用优化目标函数的连续性，将非参数化曲面拟合方法引入优化过程，使计算量大大下降，满足了工程应用的要求。最后提供的算例说明了该方法的应用过程及有效性。

Step-down-stress Accelerated Life Test——Optimal Design

A main challenge is how to design a step-down-stress accelerated life test plan of which the precise results are obtained with low cost. A novel method of optimal designs for step-down-stress accelerated life test was proposed by Monte Carlo simulation under the condition that the closed form of the optimal solution can be difficultly obtained or not exist by the traditional method of analytic optimization in a certain case. In order to decrease compute efforts which may be very large in Monte Carlo simulation based optimal designs, a nonparametric surface fitting was incorporated into optimization by using continuity of object function for meeting the application requirements. The illustration demonstrates the applied process and validity of the method.