Research On The Lightweight And Forming Technology Of Tank Car Frame

In recent years,lightweight technology has been applied in various industries,especially in the automotive industry.The lightweight technology of automobile is of great significance to reduce energy consumption,reduce environmental pollution and improve product competitiveness.At present,various types of tank trucks play an important role in our daily life,such as transportation tanker,garbage truck,sprinkler,etc.,and the sales of tank trucks are on an upward trend every year,which has a good market prospect.For the frame of tank car,the application of lightweight is also deficient,which has certain disadvantages for long-term development.Therefore,it is necessary to carry out lightweight design for tank car.By replacing frame materials,high strength steel is selected under the premise of economy and applicability to achieve the goal of lightweight.Aiming at the selected new material,the influence rule of forming process and process parameters on forming rebound of steel plate is deeply studied,the welding process of new material is studied,and a welding method and welding parameters matching the selected material are summarized,which provides guidance for actual production.Based on the tank semi-trailer provided by an enterprise,this paper carries out research on its frame lightweight and forming process.Finite element model of frame is established by UG and ANSYS Workbench software,and then static analysis is carried out to simulate the state of frame under four conditions: bending,torsion,braking and turning.Distribution of stress and deformation is obtained,strength and rigidity of frame are checked,weak parts of frame and optimization space are determined.Then the modal and fatigue life analysis of the frame is carried out to obtain the natural frequency and vibration mode of the frame as well as various fatigue performance indexes of the frame.The static and dynamic performance of the frame is discussed to provide basis for subsequent lightweight design.Based on the dimension optimization and strength equivalent alternative design theory,as well as the results of static analysis,the frame is designed lightly.Firstly,the dimension of the frame is optimized by surface response method.The optimized frame mass is 308.11 kg,which is 17.3% less than that of 372.71 kg before optimization.Then,strength equivalent alternative design is carried out for the optimized frame.The raw material W610 L is replaced by B750 L and BS960 E.The weight is reduced by 30.8% and 38.3% respectively compared with the original frame.The optimized frame stiffness and strength meet the requirements.Finally,the economic analysis of the three optimization methods is carried out,in which the combination of size optimization and BS960 E equivalent alternative design is the most economical.Finally,the bending and overlap welding process of raw and replacement materials of the frame is studied.Welding cracking is mainly caused by structural stress concentration and welding thermal cycle.It can be solved by optimizing frame structure and welding method and process parameters.Gas shielded arc welding and laser arc hybrid welding are used to overlap fillet weld the two materials respectively.By comparing the two welding methods,it is found that laser arc hybrid welding has better welding performance,can improve joint softening and reduce the risk of frame cracking.The influence rule of process parameters on BS960 E laser-arc hybrid welding joint is studied,and the optimum process parameters range is summarized,which provides certain guidance for enterprise production.