Development of block loading spectrum for car powertrain rig test correlated with customers’ usage

Abstract

To establish the loading spectrum for rig test of a car powertrain, non-contact torque telemeter is adopted to measure the testing data, including target vehicle transmission shaft torque, rotation speed, and engine rotation speed, under the typical cases of customers’ actual usage. Then, the Process Builder module in Tecware is used to establish the gear split batch-processing model and process the customer data into target rotating rainflow counting cyclic matrix and eliminate the small cyclic loads which have relatively smaller influence on the fatigue life. Next, based on the road percentage and data collected in actual customer survey, the total cumulative damage of 90% customer is calculated according to the Weibull distribution equation, and powertrain damage calculation model for fatigue cumulative damage and its probability distribution function is examined by Kolmogorov–Smirnov. Finally, the customer data are compressed into block loading spectrum which can be identified by the rig test based on the fatigue damage equivalent principle, thus achieving the powertrain rig assembly testing life equivalent to the customers’ usage life. The car powertrain rig test can replace the full-vehicle road test, which efficiently lowers the testing cost and shortens the testing period.