Abstract
Brake squeal impacts trains during station parking, generating over 110 dB at the wheel vicinity. This disturbance is a problem for commuters and employees working close to trains and limits exploitation times. The only adjustable parameter is here the brake pad, since it is the only part with frequent replacement regarding the railway equipment lifetimes. To improve current pad design to limit noise emissions a numerical prototyping tool is required, providing noise level indicators post-treated from transient simulations of industrial brakes. Such realization is impossible without a relevant reduction strategy. The CMT (Component Mode Tuning) method integrated by SDTools makes this feasible. This model reduction is not only necessary to transient simulations but also to reduce the global computational cost of all intermediate operations. In the proposed approach, the pads must be kept unreduced to allow their interchangeability, but invariant brake parts can be reduced. A reduction basis is only relevant if it provides accurate results for various configurations of a reduced parametered model. A study of the system reduction basis sensitivity must be undertaken, which is this paper main objective. A sensitivity study methodology is then proposed and results in the form of reduced model convergence are eventually presented.
KEYWORDS – structural dynamics, reduction, brake squeal, non-linear simulations, design