A Study Of The Dumping Stability Of The Dump Tractor-semitrailer Based On Multi-body Dynamic

The paper firstly introduced the background of the subject on lifting stability of dump tractor-semitrailer. At the same time, it also elaborated the necessity and urgency, as well as the main goal and significance of research on this subject, considering the developing tendency and the actual requests of enterprise. Based on analyzing the present research situation at home and abroad of the stability of dump tractor-semitrailer in detail, and synthetically considering the enterprise's specific requests, it proposed the main content of this paper.Combined with the domestic and foreign present research situation and the research content of this paper, the multi-body dynamics theory and the topological optimization theory were selected as theory tool. The multi-body dynamics theory is used to research the various factors' influence on the lifting stability of dump tractor-semitrailer, and the topological optimization theory for optimized design on the parts. Then the paper analyzes these two theories concretely.The stability of dump tractor-semitrailer includes stability of the part of lifting mechanism and entire vehicle stability. Obviously the stability of the part of lifting mechanism influences the entire vehicle stability, but there are much more factors influence the entire vehicle stability at the same time. Therefore, it researched the stability of lifting mechanism early. With comprehensively analyzed each part of the lifting mechanism, it was concluded that the triangle arm is the weakest component of lifting mechanism. Based on the force analysis of the triangle arm in its ordinary circumstance, the paper established a parametric multi-body dynamic model of the flexible connected lifting mechanism, and also studied the factors which influence the stress condition of triangle arm, such as the mass eccentricity of the boxcar, the mounting error of the triangle arm and the mounting error of the joint point of the boxcar and frame.Considered the triangle arm is extremely and easily influenced by the additional torque and its self-bad structure stability, the paper carried on the structure optimization design to the triangle arm. By using the variable density means, the triangle arm was topology optimized under the six typical force conditions during the lifting process in finite element software HYPERMESH. It was shown that the anti-twists function and the anti-bends function have been remarkably improved, and its weight has been reduced effectively.Then, the paper researched the modeling method of entire dump tractor-semitrailer. Dump tractor-semitrailer is a complicated multi-body system. Combined with the content of this paper, model scale and model precision, it simplified the real dump tractor-semitrailer and got the multi-body dynamic model .After degree of freedom and simulation check ,it confirmed that the model is credible, which can be used to research the damping stability of dump tractor-semitrailer.Eventually, the paper studied the influence of the flexibility of frame and ground status on the damping stability of dump tractor-semitrailer. From changing the flexibility of frame in five models, the paper researched the influence of the flexibility of frame on the static stability and dynamic stability of dump tractor-semitrailer. The ramp, roughness and jackknifing were chose as the typical ground status to study the influence of ground status on the damping stability of dump tractor-semitrailer.