Study on the frame load spectrum combining mileage and percentile extrapolation

In order to get the load spectrum that reflects the actual operation condition of agricultural machinery, this paper proposes to compile the load spectrum of frame by combining the method of load mileage extrapolation and percentile extrapolation. In this paper, the research object was carried out in the frame of vegetable tool carrier to study load spectrum and fatigue life. The finite element analysis of the frame is carried out, and a set of stress load test system is established based on the analysis results, and the stress time course is obtained under typical working conditions. The time domain signal is converted into frequency domain signal by rainflow counting method, and frequency statistics are carried out. According to the “From-to” matrix, the “Mean based ellipse” kernel function is used for non-parametric rainflow matrix extrapolation, considering the influence of different drivers in the actual operation, the load of three conditions is extrapolated by percentile. According to wave center method, developing eight two-dimensional load spectrum of the vegetable tool carrier frame and one-dimensional load spectrum that reflects of actual loading situation, which provides a reference for the compilation of load spectrum in agricultural machinery.