Semi-trailer With Triaxial Leaf Spring Equalizing Suspension Simulation Analysis And Structural Improvements

An automotive suspension is an actuating system between frame and axles for supporting car body and cushioning the ride. It is one of the main factors for ride characteristic, produces important contribution to automotive ride security, trafficability characteristic, stability and adhesive performance, and it is the important content of automobile general layout and movement check. With the development of mathematics, engineering mechanics, computer information technology, and the gradually sophisticated multibody dynamics, the application of ADAMS to simulation and analysis is an effective method for suspension design, analysis and optimization.On the basis of the summarization of the development history, present state and the model building method of multibody dynamics theory in the paper, a detailed research from building CAD model, and nonlinear multibody dynamics model, to simulation and analysis, then to structure parameters'optimization about the elastic part, leaf spring, and the whole suspension system is did using the engineering software, CATIA and MSC.ADAMS. The mechanism of tandem suspension and the main influencing factors is discussed through mechanics theory of suspension in the paper; A simulation and analysis for leaf spring model and its dynamic characteristics is did; After the simulation and the definition of evaluation criterion, the reason of movement interference while the semi-trailer running under the limiting conditions is found, and the structure optimization scheme is advanced; The influence rules of every single structure parameter to lifespan of tires are found though the research on the influence of the length and assembly angle of tension bar to tires durability in ADAMS. And besides, a scheme of assembly design optimization for the maintenance and repair is advanced in the paper.Modeling of the leaf spring is a difficult point in the paper. The leaf spring in semi-trailer suspension is composed of discrete rigid bodies that are jointed together by Timoshenko beams, with which we can simulate hysteresis resulted from the nonlinear characteristics by the application of sine loads.The combination of VPT and other CAD or CAE software is the direction of domestic suspension design and analysis for the future, and the paper has done some discussion and research in this domain combined with engineering problem. Based on the experiences of suspension design, the traditional motion analysis method is used for leaf spring's deformation analysis and movement mechanics research of suspension system; Computer tridimensional modeling technology is used for complex modeling, such as supporting frame and balance arm, and assembly design of leaf spring; The VPT is used for vertical motion analysis under limiting conditions, suspension longitudinal dynamics analysis of hard braking, and the research of tires durability.