Commercial vehicle chassis component fatigue load spectrum extraction method

Abstract

The invention discloses a method for extracting a fatigue load spectrum of a whole-vehicle chassis part of a commercial vehicle. The method comprises the following steps: formulating a test field road test scheme and collecting a real vehicle test field durable road surface signal; establishing and checking a whole vehicle rigid-flexible coupling multi-body dynamic model; the wheel mandrel head displacement is obtained through an iteration reverse solving strategy, and convergence judgment is carried out according to the time domain, the frequency domain and the relative damage value; and if the convergence result meets the standard, driving the whole vehicle rigid-flexible coupling multi-body dynamic model to carry out loading simulation and extracting the fatigue load spectrum of the whole vehicle parts. According to the method, the influence of tire parameter characteristics which are difficult to obtain on the whole vehicle simulation load result is avoided, the real user road condition is restored to the maximum extent, the accuracy of fatigue calculation is ensured, a good guiding effect is achieved on the design of a cab of a modified vehicle type in the later period, the fatigue durability performance can be predicted before sample vehicle production, and the service life is prolonged. In addition, the device has an important reference value for researching the system-level fatigue durability of the automobile.

Description

technical field [0001] The invention relates to the technical field of vehicle and component structural design, in particular to a method for extracting fatigue load spectrum of chassis components of a commercial vehicle. Background technique [0002] Commercial vehicles are widely used in the road transportation industry due to their absolute advantages in transportation distance, load capacity and ton fuel consumption. However, due to the harsh operating environment and complex working conditions, the problem of fatigue damage is serious; according to research, about 80% of commercial vehicle structural components % of failures are caused by fatigue damage; therefore, how to accurately predict fatigue life and improve fatigue durability performance is an urgent problem to be solved in the automotive industry. [0003] The traditional automobile fatigue life evaluation method is to conduct road durability tests on the proving ground. If there is a problem of durability fail...

AI Technical Summary

Problems solved by technology

Among them, the most typical one is the VPG (Virtual Proving Ground) simulation technology. This method collects and strengthens road surface digital information through the proving ground and establishes an accurate multi-body dynamics model of the vehicle (including the tire model), without the need for a real vehicle road test. The component fatigue load spectrum can be obtained; however, there is no measured signal as the monitoring basis, and the excitation response accuracy of the vehicle multi-body dynamics model under complex road conditions cannot be verified, especially the highly nonlinear problem between the tire model and the ground. It makes it difficult to control and determine the accuracy of the VPG simulation solution

[0004] At present, the methods for extracting the fatigue load spectrum of the chassis components of the vehicle by means of CAE simulation mainly include the direct loading method and the constrained body loading method, which have the following limitations: the direct loading method directly applies the six-component force signal measured on the proving ground to the wheel. , since the car body is in a free state during the road test, loading the vertical force on the wheel center of the unconstrained vehicle model will cause the model drift to diverge and not converge; the constrained loading method is to constrain the attitude of the car body, and then load the six points of the wheel center on the test site Due to the control of the attitude of the vehicle body, there is a certain difference between the extracted load spectrum and the real force condition of the reinforced road surface of the test field.

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