Based On Car Carriers Pavement Frame Vibration Fatigue Loads

The frame is main strcuture of vehicle for bearing, its strength, stiffness,dynamic characteristics and fatigue performance have great influence on vehicle’s safety. In the actual, frame strength more dependent on the vehicle vibration and random load response of the frame.A car transporter produced by a factory in Yangzhou emerges same crack in the area of frame after running. Therefore, taking the crack of semi-trailer frame as the research object, considering the road surface roughness is the cause of the frame vibration, doing static analysis,dynamic analysis and fatigue damage analysis with finite element calculation software and simulation software. Main research contents are as follows:1. Analysis on the frame, frame random vibration fatigue by domestic and overseas, we did a lot of research on status of numerical value simulation of fatigue. On the basis of reading fatigue theory, including fatigue load spectrum of the statistics, analysis of stress fatigue and strain fatigue analysis, crack analysis, vibration analysis, our choice is suitable for the fatigue assessment methods to object of this article.2.Setting up finite element model of frame and carried on statics and dynamics analysis.Finishing3d modeling of frame in software UQafter extracting of neutral surface, selecting appropriate cell type, meshing,then doing static analysis,we can know the static strength and stiffess in the stationary state; doing prestressed modal analysis,we can get inherent frequency and vibration mode,which will provide the basis for judging frame vibration characteristics;doing frequency response analysis,we can get the transfer function of the frame and further analyzing the vibration characteristics of frame.3. Doing road test and measuring the car transport vehicle leaf spring force.To test frame’s dynamic performance,we collected the acceleration signal in the location of leaf spring,and estimated the leaf spring force on the frame in load time history on the basis of reasonable simplified model of leaf spring, and converted force load in time history into load spectrum in the frequency domain.At last, we got a complete PSD analysis on force loading, and completed the data connection between software.4. Doing fatigue analysis for frame. According to dynamic analysis of frame frequency response characteristics, test measured load spectrum, the structure of the material S-N curve,within a given frame transfer function, load spectrum, material S-N curve,on the basis of Dirlik model and Goodman correction in Msc. Fatigue,we can estimate fatigue life and fatigue damage of vulnerabilities in frame under the particular condition.