Structural Analysis And Optimization Design Of Rail Flat Car Chassis

The rapid development of China's railway transport and the continuous improvement of railway transport capacity have had an important impact on China's economic development.In order to improve the railway transportation capacity,the main development direction of railway freight transportation is to speed up and heavy load.Commissioned by a railway company,we developed a certain type of track flat car.Track flat car is mainly used in railway works,electricity and other departments,railway construction and line maintenance plays a prominent role.The bottom frame is the main stressed part of the track flat car,bearing all kinds of loads,so it is necessary to conduct an in-depth study of the bottom frame,to ensure that the bottom frame has good performance.Type based on the orbit flat car chassis as the research object,in the understanding of flat car development situation at home and abroad as well as flat car chassis,on the basis of research status quo,first of all,to characteristics and stress of the chassis of the beam structure is studied,this paper introduces the theory of finite element method(fem)and related software,use SolidWorks chassis 3 d model is established,and guide into the chassis of the finite element model is established in ANSYS Workbench.Then,after comparative analysis of domestic and foreign standards,TB/T 1335-1996 standard and EN 12663 standard were selected for finite element analysis of the chassis.Combined with the calculated load specified in the standard and the load combination mode,the stiffness condition,the static strength condition and the fatigue strength condition of the bottom frame were determined,and the deflection of the central beam of the bottom frame under the stiffness condition,the maximum equivalent stress under the static strength condition and the principal stress under the fatigue strength condition were calculated respectively.The stiffness of the bottom frame is evaluated according to the flexural span ratio of the middle beam of the bottom frame required in TB/T 1335-1996.The fourth strength theory is used to evaluate the static strength of the frame.The fatigue strength of the chassis was assessed using the method described in the ORE B12/RP 17 report.The results show that the chassis has enough stiffness and strength to meet the requirements of the standard.Then,the modal analysis of the chassis is carried out,the first 12 modes of the chassis are extracted,the natural frequencies and modes of each order of the chassis are obtained,and the dynamic characteristics of the chassis are studied.The results show that the chassis meets the requirements of modal frequency and provides guidance for the chassis to avoid resonance.Finally,sheet thickness and section sizes as design variables,minimizing chassis quality as the objective function,under the condition of multiple constraints,the chassis structure,optimized design and check on the reference standard,make the chassis quality reduced 6.43%,and meet the stiffness,static strength,fatigue strength and modal frequency requirement,realized the underframe structure of lightweight.