RANDOM RESPONSE & FATIGUE OPTIMIZATION IN THE FREQUENCY DOMAIN
Altair EmployeeFrequency based methods for random response and fatigue are becoming more widely used in the automotive industry. The use of PSD's (Power Spectral Densities) coupled with system properties in the frequency domain (transfer functions) offers significant benefits over time based approaches in terms of analysis time, model size that can be handled, and most importantly, such methods facilitate the incorporation of optimization techniques to find the optimal values for parameters such as shell thicknesses, material properties, weight.
In this paper, application of frequency based methods for random response and fatigue optimization is demonstrated on an automotive full body system. The process followed uses MotionSolve generated body loads and OptiStruct stress results as input to a CAEfatigue VIBRATION analysis. This process is executed from HyperStudy for optimization and the results produced are then post processed in HyperView. Using the process outlined, it is feasible to achieve considerable weight reduction while maintaining desired fatigue life.