A scientific method for compiling the load spectrum of transmission shaft for hybrid special vehicle based on parameter extrapolation

To compile the load spectrum for the transmission shaft in hybrid special vehicles with high reliability, this paper employs the parameter extrapolation method for load spectrum compilation. By collecting experimental real vehicle torque load data and related driving records, the operation process of the special vehicle would be divided into 5 typical operating conditions. Throughout the pre-processed load data, the rainflow counting method is applied to develop statistically analysis and distribution-fitting. Based on the probability statistical distribution results, it could indicate that: the amplitude values for each operating condition follow a lognormal distribution; the means value for each operating condition follow a 3-parameter lognormal distribution, and they are mutually independent. Accordingly, the load extremes and frequencies are extrapolated for the target life cycle, and the rationality of the extrapolation is verified. Based on the extrapolation results, an 8-level two-dimensional load spectrum and a one-dimensional program spectrum are compiled. In general, the research results provide a foundation for the reliability testing of hybrid special vehicles.