Authors: Kenji Sumi, Kenichi Yamamoto, Ludo Gielen, Luc Meulewaeter
Addresses: Toyota Motor Corporation, Japan. Toyota Motor Corporation, Japan. LMS International, Belgium. LMS International, Belgium
Abstract: As a result of the requirements to shorten the development cycle of new engines, CAE techniques become increasingly important in the early design stages. More specifically, the complex task of vibro-acoustic optimisation, traditionally an end-of-cycle task, is now shifting towards the pre-assembly phase. Structural and acoustic modelling methods, used to predict the performance in terms of noise, vibration, engine dynamics and durability, rapidly evolve to being key tools in the design processes. Traditional CAE analyses of powertrains rely on large-scale FE-models, describing the engine, transmission and auxiliaries in much detail, and lead to high model development times and high computational times. However, because of the limitations currently put on the total design cycle duration, modelling methods need to be able to handle a mixture of pure analytical design models and experimentally obtained dynamic characteristics. Based on analytical vibro-acoustic component models, an initial predictive assembly model is built. Excitation forces resulting from dynamic simulation or from experimental identification on existing engines are used to load the model for the evaluation of the performance or design changes in terms of absolute noise and vibration levels. The noise and vibration quality can thus be evaluated at assembly level and next cascaded down to requirements at component level. Whenever available in a new development phase, the measured dynamic characteristics of prototyped components are integrated into the total model, to refine the virtual prototype of the assembled product (see Figure 1). This paper covers the investigative application of these hybrid vibroacoustic simulation techniques. The described project has been executed as under cooperation between Toyota Motor Corporation and LMS Engineering Services in order to establish the above process and validate the simulation techniques. The Toyota 3S-FE engine is used as a benchmark engine throughout this paper.
Keywords: hybrid simulation; NVH; powertrain; powertrain modelling; vibration; vibro-acoustic optimisation.
International Journal of Vehicle Design, 2002 Vol.29 No.1/2, pp.149-159
Available online: 15 Aug 2003 *Full-text access for editors Access for subscribers Purchase this article Comment on this article