Structure Design And Optimization Of The Monocoque Semi-trailer Body For Logistics

With the development of the logistics and the expressway network, there are more and more semi-trailers exist in china. The rapid development of the semi-trailer industry has become the only way to promote the progress of China’s automobile industry.After a century’s development, the structure of the vehicle body has undergone three main stages of development as a non-load type, semi-load type and full-load type. When there is a greater load or impact load on the vehicle body, the full-load type of body structure can diffusion the power flow to the skeleton structure of the body rapidly. That prompted the skeleton structure of the body to achieve a steady state and enhanced the safety performance of vehicle. Therefore, the full-load type of body structure has been widely used.As a carrier of assembly and parts, the body skeleton is the most important load bearing component part in wholly-carrying vehicle. The pros and cons of its structural performance will directly affect the fatigue strength and service life of the body frame. In structure, the general arrangement of Vehicle must meet the requirements of design; In intensity, it should be able to withstand the maximum static load and the impact load of the normal operations; In addition, the body skeleton should have enough bending stiffness and tensional rigidity to maintain normal operating status in a variety of conditions.With the deepening level of social concern on the safety performance and the lightweight requirements of operational vehicle, the whole bearing structure will become inevitable direction in the development of the body form of semi-trailer. Usually, the body structure design need considering the two requirements of "function" and "structure performance". However, in reality, the two are often mutual restraint. Arbitrarily increase the carriage height for multi-loading, it is not only illegal, their safety performance will also be greatly reduced. To break the routine, in these paper, we proposed a number of innovative exploration on new semi-trailer body structure which provide an effective reference for the booming of special purpose vehicle industry in China.In these paper, we proposed two innovative structures of the semi-trailer body, one of them is the double carling structure, and the other is the spine keel structure. And then analysis the two innovative structures and compares the data of experimental. The main research methods in this paper are as follows:Firstly, the new body skeleton concept is proposed, then the body structure will be redesigned or adjusted based on the design standard, and the geometric model of the semi-trailer should be established; secondly, the load and the boundary conditions are controlled by using the finite element method; finally, the feasibility of the new program is verified by the structural performance evaluation standards. The main purpose of this paper is to do some innovative exploration of the semi-trailer body structure, analyse the structure of two innovative programs by using the finite element method, and provide an effective reference for the semi-trailer design.According to this purposes, this paper launches the work from the following two aspects:1) At first, the double carling structure and the designing program are proposed by the standards of the body constructional and functional requirements. In order to verify whether the program can meet the mechanical properties of the semi-trailer body, we analyze the body structure performance indicators (strength, stiffness and modal) by using the finite element method.2) The problems of the original design are found and the spine keel structure program is proposed. In order to explore the body structure performance of the new program, we analyze the body structure performance indicators (strength, stiffness and modal) by using the finite element method, and compare the experimental data.