| SF33900type220t mining dump truck works in a complex environment and poorroad conditions, driving a big load. The vibration under random excitation of roadsurface will cause the fatigue failure of dump truck components, especially the framewhich is the main part of bearing load of the truck. Fatigue crack possibly initiatesnear the weld seam of weld structure under the alternating load. After a certainrunning time, very few mining dump truck frames crack in some weld seam.The CAE (computer aided engineering) technology is applied in the automotivedesign more and more widely with its development and improvement. In order topredict the fatigue life of SF33900type mining dump truck frame and frame weldseam, the corresponding CAE technologies are applied on a truck frame including offinite element analysis, multi-body dynamics simulation, fatigue life analysis andstructural optimization design to construct a comparatively unabridged applicationsystem of CAE, which provides guidance for the design in the future.1. The multi-body dynamics model of truck body structure is established.According to the actual road condition for driving by dump truck, thecounterforce-time course of fully loaded and unloaded are gained by using grade Croad spectrum as input. So it provides load spectrum data of fatigue life analysis. Theextreme torque condition simulation of the dump truck over pit and boss is completed.2. The finite element model of the frame is established by using shell element inHypermesh software. The large parts are simulated by using Mass element and thesuspension is simulated with the spring element. The static strength characteristics ofthe frame are analyzed. At the same time,due to the complex running conditions of thedump truck as well as the importance of safety, the typical dynamic strength analysisof the frame are done in various extreme conditions. The stress distribution indynamic load is obtained based on Hypermesh, and the result of calculation iscompared with that of the experiment. The results consistent, which validates thesimulation model.3. According to the S-N curve, the fatigue life of the frame in the fully loadedand unload are obtained using Msc.Fatigue software based on dynamics analysisand static analysis of the frame. Then further more reliable weld fatigue life isanalyzed with SEAM_weld method. The results of the fatigue life shows that the fatigue life of existing frame can meet the basic requirements.4. Finally, topology optimization is analyzed on the frame, with flexibility for thegoal. According to the result of topological optimization, it puts forward a new designscheme of frame model, and then static analysis, the extreme torque condition andfatigue life analysis are done on the new frame model. The strength and the fatiguelife both increase comparing with the original frame model. This paper provides somereference and guidance for later analysis and the corresponding engineering analysiscode according to some of the accumulated data. |
