Development of Component Mode Synthesis Method by Using Parallel Computing

Ichiro Hagiwara, Masabumi Suzuki
Vehicle interior noise reduction is very important, because it improves marketing characteristics of vehicles. Computer simulations are widely used as design tools for vibration problems. In particular, finite element analysis is one of the most powerful tools for dealing with them. However, even though the problems are analyzed using supercomputers and can be assumed to be linear, the applications of finite element simulations are still limited. For example, the finite element analysis results
more » ... nt analysis results for vehicle bodies can be successfully applied to frequency phenomena up to 100Hz, but they are not applicable in the higher frequency range, because the vehicle bodies have very complex vibrations when their frequencies become high. The component mode synthesis (CMS) method is very efficient for dealing with such large complex structures, because a very large number of degrees of freedom of the model can be reduced to a problem of smaller size by using the CMS method, which can be computed using computer with less storage capacity. In CMS method there are three methods. One is based on displacement mode synthesis (DMS) method, acceleration mode synthesis (AMS) method and Ma-Hagiwara mode synthesis (MH) method. Here I show the superiority of the method, based on MH method, using the real vehicle car model. On the other hand, since we are dealing with a large scale problem, we have developed PC cluster system for static problem. The PC cluster system for dynamic problem is also being developed. But for the time being only DMS based component synthesis method has gained successful results. In the cases of AMS and MH there occurs the inverse calculation of matrix, so the parallel computing is difficult. Here a new technology for solving it is proposed.