Accelerated testing (AT) is an effective testing method for evaluating the reliability of highly reliable products. In many applications, such products are often subject to multiple stresses in actual working environments. Then, how to design the load spectra for multi-stress AT becomes a critical issue. In this paper, a new load spectra design method is proposed to overcome this challenge. Considering the properties of multiple stresses, a novel multi-stress loading matrix (MSLM) is modified to fully describe the load spectra in actual working environments and to generate the corresponding load spectra for AT. For illustration purposes, an inverse Gaussian (IG) process incorporating life-stress relationships is adopted to model product degradation under multiple stresses. A case study on a type of hydraulic piston pump is provided to demonstrate the use of the proposed method in guiding the load spectra design for multi-stress AT.

加速测试（AT）是评估高可靠性产品可靠性的有效测试方法。在许多应用中，此类产品在实际工作环境中经常受到多重应力。那么，如何设计多应力 AT 的载荷谱就成为一个关键问题。在本文中，提出了一种新的载荷谱设计方法来克服这一挑战。考虑到多应力的特性，修改了一种新颖的多应力加载矩阵（MSLM），以完整描述实际工作环境中的载荷谱，并生成相应的 AT 载荷谱。出于说明目的，采用包含寿命-应力关系的逆高斯 (IG) 过程来模拟多重应力下的产品退化。