Virtuell hållfasthetsprovning av en turistbuss
The competitive nature of the automotive industry has always implied a necessity to improve product development concerning time-to-market, cost and product quality. As capacity of computer-aided engineering (CAE) tools has evolved, so has the strive for simulation-driven design. Virtual durability testing using full vehicle models is one of many challenges posed in front of vehicle manufacturers when computer simulations are given a key role in product development.This thesis has been initiated as a preliminary step towards implementing dynamic virtual durability testing in the development of buses and coaches at Scania. The objective has been to assess the predictability of a full vehicle coach model and to what level of precision structural loads can be predicted. Previously performed proving ground testing of a Scania Touring coach has been the basis for the modelling and simulations in this thesis.A virtual model of the Scania Touring coach has been created in multi-body simulation software package MSC.Adams. The chassis frame and body structure of the coach has been incorporated as a flexible body to depict its dynamic properties and structural loads. Approximations of the coaches structural damping were derived by means of reverse engineering via design of experiment. The model was analysed using two different types of full vehicle simulations, in this paper referred to asVirtual Test Rig and Virtual Proving Ground. In the first mentioned simulation procedure, test rig software RPC Pro has been used in conjunction with Adams to generate displacement inputs at the wheel spindles. These displacements are back-calculated from response signals measured during the physical test on the proving ground. In the latter simulation, the unconstrained model was instead driven over a digitized version of a proving ground road profile.The model performance has been evaluated against the measured data from the physical test. Results from virtual proving ground simulations show good correlation of vertical spindle loads but not as well for spindle loads in lateral and longitudinal directions. Acceleration responses in the coach structure demonstrated evident damping dependency as expected. The evaluated strain responses were non-conservative for all derived structural damping approximations. Simulations in the virtual test rig has shown that accelerations in the coach body structure are possible to replicate with high accuracy. The results from the virtual test rig demonstrated well-correlated strain responses for two of the four evaluated locations.