Editing And Extrapolation Of Durability Load Spectrum Of Dump Truck

In order to adapt to the ever-increasing competition in the global automotive industry and shorten the development time of new models,the rapid durability evaluation technology has become the main method for product verification by domestic and foreign vehicle and parts companies.The rapid durability evaluation methods include: road test in the automobile proving ground And indoor bench test.The road test durability specification of the proving ground is formulated based on the full life cycle load damage of the vehicle under the use conditions of the user.Since it is difficult to obtain the full life cycle load of a vehicle,it is necessary to extrapolate the load data reasonably to obtain the full life cycle load spectrum.The automobile indoor bench test can improve the test efficiency by editing the load spectrum,so it is widely used.The paper is based on the actual road load data of an 8×4 dump truck.For the road test of the proving ground,the multi-criteria decision-making technology is applied to load extrapolation,and the multi-objective genetic algorithm is applied to establish the durability specification of the proving ground for related users;for indoor bench test,the Hilbert-Huang transform was used for load spectrum editing.The topic of the thesis comes from a school-enterprise cooperation project,which has theoretical significance and engineering use value.The six-component force sensor,strain,and acceleration sensor are used to collect the proving ground and user road load spectrum data,and the load spectrum data is processed and analyzed to verify the validity of the test data.For the road test of the proving ground,based on the extrapolation of the time domain load of the POT model,a threshold selection method for multi-criteria decision-making is proposed.From the perspective of the fitting effect of the Generalized Pareto Distribution function,the entropy weight method is used to determine the weight of each fit test criterion;the TOPSIS method and the gray correlation method are used to define The comprehensive contribution coefficient of each candidate threshold is calculated,and the comprehensive contribution is used to determine the optimal threshold of the sample data.50 sets of simulation data are used to verify the feasibility of the proposed method.Taking the vertical force load of the left front wheel of the user’s road as an example,the extrapolation of the load is realized and the effectiveness of the extrapolated load is verified.Based on the principle of equal damage,the difference between the extrapolated load damage and the combined damage of the proving ground is used as the objective function,and the cycle times of the road conditions of the proving ground are used as the design variables to establish the "user-test field" correlation model,and the multi-objective genetic algorithm is used to realize the model Solve.Aiming at the problem of selecting the optimal solution from multiple non-inferior solutions,using the average and standard deviation of the relative damage ratio of each measuring point as the selection criteria,the optimal solution is obtained,and the durability specification of the automobile proving ground for related users is established.For the indoor bench test,for the acceleration of the load spectrum editing,a method for editing the automobile durability load spectrum based on the Hilbert-Huang transformation is proposed.Taking the user’s road left front wheel vertical force load spectrum as an example,it is edited and compressed.Contrast analysis with the editing method based on damage preservation.The results show that the editing method based on Hilbert-Huang transform is better than the traditional editing method based on damage preservation under the premise of the same amount of pseudo damage retention.