Virtual operational strength analysis for commercial vehicles

Abstract

Customer demands and governmental emission regulations require new lightweight and electro mobility concepts in the commercial vehicle market.The necessary design changes have a significant impact on both, the structural strength and the dynamics of the chassis and the body. The evaluation of the chassis components and the body in terms of structural dynamics and operational strength at an early stage of the development process plays an important role for a time and cost effective validation process. Using simulation methods, the virtual vehicle can be analyzed long before a physical prototype is available which allows faster structural design optimizations. The virtual rough road testing combines multiple simulation disciplines and takes the full vehicle dynamics into account. Starting with the full finite element model for strength analysis, a superelement is generated using component mode synthesis. This superelement is incorporated in multibody rough road simulation to consider the elastic body deformations. The multiaxial loading history and the material data of all components are subsequently used in the operational strength analysis to determine the resulting hotspot regions and to derive structural optimizations. For a reliable operational strength forecast, an accurate prediction of the input load history is important. Therefore, the modelling of the front axle used in city busses is investigated. A flexible model of the axle is used for a stress comparison with real world test track data. In a further step, the necessity of the flexible body is evaluated with a comparison of the resulting bushing forces attached to the frame structure.KeywordsOperational StrengthFlexible BodiesLoad Validation