Design Technology of Accelerated Life Test Based on the Load Spectrum Compilation and D-efficiency

The accelerated life test is a highly efficient method for long life evaluation of products, but the operation profile validity and test time optimization are unavoidable in the actual application. Herein, a design technology research was conducted. First, the load spectrum of temperature and vibration on operation profile of a rail transportation equipment was measured. Thus the load spectrum was compiled based on 3-parameter rain-flow counting method and operation profile was equivalently designed based on Corten-Dolan cumulative damage model to ensure the validity. Then step-stress accelerated life test model based on generalized Eyring model and Weibull distribution was developed. The design method of step-stress accelerated life test with the shortest test time was given. Finally, the design method was applied in signal output board of rail transportation case. The residual life assessment was made for the 2-year-used equipment taking the current usage profile as the first step of the step-stress accelerated life test which verifying the design method.