Abstract: In order to research the fatigue reliability of the vehicle powertrain system, a new load spectrum weave technique correlated customer usage is proposed based on automotive powertrain indoor test. It includes the compressive approach to random load time history based on rain-flow counting method and statistical theory, the speed and gear information corresponding the compression load are also received in the reconstruction spectrum. The traditional relationship between torque level and time is translated into torque level and speed range, meanwhile, the gear position is recorded. The statistical distribution based on different levels of Torque vs speed and vs gear are obtained. Using peak over threshold statistical extreme value theory, a method for extrapolation in the time domain is presented, the extrapolated load spectrum obtained from the extrapolated time signal contains the information about speed and gear. Defining new sampling rate and spline interpolation methods are used to modify the random load spectrum to the test rig properties. The technique can combine the real customer usage data to vehicle powertrain test bench, and avoid the test blindness. Provided an important foundation for precisely evaluating automotive powertrain reliability and establishing a reasonable principle of automotive powertrain reliability indoor test.

Key words: driveline, load spectrum, test bench, time-domain extrapolation