The Lightweight Design Of Cargo Box Of Heavy Commercial Vehicle Under Full Vehicle Environment

In order to reduce the structural weight and increase the cargo safety, the automotivedesigners pay great attention to optimize the vehicle structure. Therefore, weight optimizationof components of heavy trucks is becoming more and more important. There is the complexelasticity coupling relations, as the commercial vehicle cargo box and frame are connected withsubframe. Currently, most of the optimization designs of the commercial vehicle are limited tothe individual component and it is difficult to deal with auto components with the complexcoupling relations. Therefore, the main research of this thesis is the lightweight design of heavycommercial vehicle cargo box under full vehicle environment.Focusing on the complete optimal problem, a new conception of static modal stiffness andits sensitivity are introduced. The generalized inverse optimization method of cargo box isdefined based on the statical modal stiffness sensitivity. The present method is used to deal withthe lightweight of heavy commercial vehicle cargo box under full truck environment. First ofall, a finite element model of the vehicle by using HyperMesh module of the HyperWorkssoftware is established. The vehicle is divided into the cab, the cab support spring, suspensionspring, frame and cargo box. The cargo box is divided into the left and right side plates, thefront and back dam-board, the strengthening rib of the left and right side plates and backdam-board, the strengthening rib of front dam-board, the subframe, the beam and carling ofbase plate. Using Radioss and HyperView module of the HyperWorks software to analyze thestatical finite element model of full vehicle under torsion and bending conditions. Bycalculating the statical modal stiffness sensitivity, filter out the master parts as design variables.And then, according to statical modal stiffness sensitivity information, the design parameterscan be defined, and the generalized inverse optimization method can be used to get the resultsof lightweight design of cargo box. Finally, the statical stress analysis of the cargo box in the whole vehicle situation is studiedand compared with the original frame under three load cases. The comparison of dynamiccharacteristics is also studied in standard load condition. The results of the lightweight designof heavy commercial vehicle cargo box show that the presented method, the generalized inverseoptimization method based on the static modal stiffness sensitivity, is effective and valid. Thismethod can be also used to optimize complex system with elastic coupling relationship.