A Coupled Simulation Approach for the Quantification of Impact Events in Automotive Applications

Squeak and Rattle are the most obnoxious noises, affecting the perceived quality of an automobile interior. Minimizing or eliminating these transient events poses a great challenge in vehicle construction as they are generally discovered late in the product development cycle. Identifying and quantifying these issues at the design and virtual validation stage is of prime importance. Current simulation methodologies estimate the occurrence of these events by measuring the relative displacement between the interacting parts. Solving this problem using linear simulations do not accurately reflect real-world non-linear mechanical behavior and most importantly, quantifying the noise caused by these impact events. Capturing a suitable impact behavior is essential along with the quantification of noise generated by these events is necessary for understanding the severity of the problem. This paper suggests a method based on non-linear impact analysis for quantifying the noise produced during a rattle event. To represent this rattle event a simplified geometry consisting of two plates was considered. Contacts were defined at the impact points, and a non-linear transient simulation was run with a sinusoidal load as the input. The impact forces were measured at the contact interfaces and then used to calculate the SPL using the Statistical Energy Analysis (SEA) method at a suitable distance from the impacting event. In addition, a comparison study was performed to observe the effect of increase in excitation frequency. The implemented method would provide an advanced approach to assess noise produced due to impact, and it could be scaled up to undertake assessments for various sub-systems and vehicle assemblies, especially the interior trim parts to attenuate the noise generated by rattle events.