Optimization Design And Fatigue Analysis Of Wing Open Vehicle Body Frame

With the rapid development of communication and transportation industry, wingopen van body is getting used widely in special purpose vehicles. The skeletons ofwing open van body is used to support van body and attach the internal and externalskins. The structure style of van body skeleton have a big effect on the strength、stiffness and mass of van body. Structure style of the good skeletons should meet therequirements of strength and stiffness and make the van body lightweight.The study origin from the development item of a certain type wing open bankworking vehicles which is used in villages and towns. The van body is long, thedeformation of some parts is large in the using process. As a result, a structure strengthoptimization design for the van body skeleton is needed. At the same time,in the actualusing process of the vehicle, the damage of skeleton structure is often caused byfatigue failure. Therefore, it is necessary to make a fatigue life analysis of van bodyskeletons after optimization.In this paper, the structure design of van body skeleton of a certain type wingopen bank working vehicles is studied.The design goal is to raise the stiffness of thestructure, the topology optimization method was utilized to make a optimize design ofthe structure,then a fatigue analysis of van body skeleton after optimization designwas made. The primary research content is put as follows:1) Structure style and size parameters of different parts in wing open van bodyskeleton is analyzed; A three dimensional geometrical model of wing-open van bodyskeleton was built.2) The finite element model of van body skeleton was built on the basis ofgeometrical model; Design area and non-design area was divided in the finite elementmodel, design variable、objective function and constraint function was defined, thetopology optimization parameters was set up, the topology optimization model of vanbody skeleton was built.3)A topology optimization of van body skeleton was made through analyzesoftware Optistruct, the design scheme of new van body skeleton based on topologyoptimization is formed through the engineering analysis of topology form and shape.4)A three dimensional CAD model of new van body skeleton was built; A finiteelement model of wing open van body was built based on the geometrical model, a structure strength analysis and modal analysis was made in extreme lifting condition,the distribution results of stress、deformation condition、natural frequency and modalshape of vibration of new van body skeleton model was gotten; Compare new vanbody skeleton’s structure performance with the original one, the results indicates thatthe topology optimization reach its optimization goal.5)The fatigue analysis model of new van body skeleton was built in nCodesoftware according to the Miner rule in linear fatigue cumulative damage theory, thestructure’s distribution map of fatigue life was gotten, the position of the mostdangerous node and its fatigue life was determined; Fatigue calculation resultsindicates that the structure of van body skeleton after topology optimization meet therequirements of fatigue life.