This paper presents advances in non-linear simulations for systems with contact-friction. Presented applications deal with squeal analysis of industrial (600,000 DOF) brake models. First a reduction method allowing to keep the exact system real modes is proposed for all simulations. For transient simulations a modified non-linear Newmark scheme is used to evaluate the apparition of limit cycles. A space-time limit cycle decomposition is then performed to correlate complex modes and the limit cycle. Although the shapes are close, the comprehension in the system behaviour is much finer in the time domain; in particular, since saturation patterns are then available. Since transient computations remain costly (12h), the end of the paper focuses on quick continuation methods to evaluate saturation threshold based on complex modes trajectories. Encouraging results are obtained, making the concept viable for industrial systems.

Vermot des Roches, Guillaume*, Balmes, Etienne - SDTools, Lemaire, Remi, Pasquet, Thierry - Bosch Chassis System Brakes