Deep Integration of Reliability Analysis into CEA
Numerical method procedures for brake squeal analysis are widely accepted in industry. The approach of complex eigenvalue analysis (CEA) is successfully used to predict the appearance of squeal noise. Using simulations in an early design stage reduces time to market, saves costs and improves the physical behavior of the brake system. But many parameters are associated with a certain degree of uncertainty. To take into account the uncertainties of parameters, reliability analysis is used to determine the probability of squeal for disc brake. Stand-alone software with methods for reliability analysis is established in industry, too. The approach of using both types of software in combination was successful. The reliability analysis software restart simulation software from outside many times to get results for different parameters. The two disadvantages are the high computational effort and the process which by minimum connects two software tools. Even state of the art methods for simulation and for reliability analysis in combination cannot overcome these methodical disadvantages. To get rid of the disadvantages of separated software the only chance is the deep integration of the reliability analysis tools directly into the simulation software. Then the organization of the complete process is done by one software, based on one user interface. All time-consuming unnecessary repetitions, file transfer and additional interfaces can be avoided. Additional methodical benefits can be exploited, e.g. analytic derivatives. This integrated approach makes reliability analysis useful for industrial application. The existing simulation models need no change, just additional data for reliability analysis must be added. The run time is drastically reduced in comparison to the conventional process. The solver integrated methods for this challenging task are available in the high-performance solver PERMAS. The evaluation is based on stability maps which contain the uncertainties. Advanced methods with control of the covered analyses reduce the effort to the possible minimum. An example of CEA with several uncertain parameters shows the practical application of the advanced options of integrated reliability analysis. Maximal utilization of mathematical benefits is used for the industry oriented numerical example to show the effectiveness of the approach.