Dynamic Analysis And Optimization Of Major And Auxiliary Integral Dump-Truck-Frame

Frame is the main supporting body of dump truck. In the process of dump truck running, frame bears the excitation of road and power transmission equipment, etc. When the natural frequency of frame and the excitation frequency of other external factors producing and transmitting to the frame are coupled, frame resonance will occur, which will not only affect the frame performance, but also cause the structure and components damage and fatigue failure. Frame external excitation is the basic input of frame dynamic characteristic analysis, so how to obtain the external excitation economically,conveniently and accurately, which becomes the basic task of frame dynamic characteristic analysis. In addition, the frame, as the basic component, its structure size has a large influence on the center of vehicle gravity and dynamic characteristic and other performance parameters. Therefore, this paper researches the major and auxiliary integral frame of dump truck DT002, on the basis of the frame modal analysis, comparing the frame dynamic load histories of numerical dynamics model, multi-body dynamics model and real vehicle test measured. For the goals of first frame modal and frame weight, conduct theframe size optimization design, and achieve the low center of frame gravity and lightweight design further.To analyze the static and dynamic characteristics of the frame, first, using six component collected the actual load on road surface measuring instrument,analysis and processing to obtain the frequency domain response of the pavement load spectrum, the results show that the frame dynamic response frequency is mostly under 5Hz. Next, the finite element analysis model was built and the computed results were compared with experimental ones to obtain the first ten order modal characteristics. The analysis of them showed that the maximum error of experimental results on the natural frequencies in free conditions were less than 5% except the second and the tenth order modals.The results showed that the low-order modal was well realized, avoiding the excitation frequency of both road and engine. The results verified that the finite element model was proper. Then, on the basis of above analysis, in order to get the road excitation of the frame when the vehicle drives on the typical roads,dynamic mathematical model and multi-body dynamics model were established.After the field and road test of the whole vehicle, the results of simulation were comparative analyzed and the basic input was provided for dynamic characteristics analysis of the frame. On the basis of above analysis, by simulating the model in C and D grade of typical pavement conditions, the dynamic stress characteristic curve was got and the maximum stress position of the frame was found out. Last, on the basis of keeping the original structure ofthe frame, and considering the influence of plate thickness to low-order frequencies, the frequency sensitivity analysis on the plate thickness was done.Taking the plate thickness as the design variables, the vehicle quality and the first order modal frequency as the targets, the analysis determined the influence of plate thickness on the overall performance of the frame. The modal characteristics and the static characteristics of the optimized frame were checked in the end.This paper systematically researches the dynamic characteristic of main and auxiliary integral frame of special engineering dump truck DT002, which provides a theoretical basis of the frame improved and optimal design. On the other hand, also reserving the related technical data of DT002 frame for company and providing the technical reference of mass production of vehicle in the future.