ABSTRACT
In order to successfully test and maintain a product subjected to long-term non-operating condition, it is important to understand the design, the manufacturing process, the loads throughout the life cycle, the potential failure mechanisms, and the cost penalties associated with each design and manufacturing decision. Evaluating the distribution of failures and life expectancy can therefore be difficult because of the very long test periods required to obtain sufficient failure data. The advantages of accelerated life tests are both economic savings and quick turnaround during the development of new products or of mature products subjected to manufacturing and workmanship changes. Temperature cycle testing can be conducted to assess the effects of thermal expansion mismatches among the different components and interfaces within a product. The pressure-temperature-humidity test accelerates the effects of moisture penetration failure mechanisms. The accelerated test under random stress is usually conducted by elevating the power spectral density function of stress, displacement, or acceleration of the product.
