Analytical Method to Predict Floor Console Lid Latch Rattle Acoustic Noise

This paper is a continuation of previously published technical paper SAE 2022-01-0314. The preceding work described an analytical methodology to predict the vehicle interior trim squeak and rattle issues upfront in the design cycle using a “relative displacement” or “contact force” metric; the methodology was implemented on the center floor console armrest latch using a linear finite element model. The work is logically extended to predict the squeak and rattle issues quantitatively using now an “acoustic noise” metric, this enables a direct comparison with the physical test results and helps to further refine the design best practices. This approach combines Finite Element Method (FEM) and Boundary Element Method (BEM) to estimate structural vibration response and acoustic sound pressure respectively. This analysis process encompasses steps such as 1) conversion of frequency domain random input excitation to time series data, 2) estimating non-linear time domain structural response, 3) estimating acoustic radiation using the boundary element method and 4) generating sound metrics in terms of Zwicker loudness. The physics of latch impact phenomenon at the contact interface resulting from road excitation which acts as a secondary excitation source and capable of exciting the higher frequency resonance modes of adjacent panels were captured in the analytical model. Though the resulting radiated acoustic noise due to panel vibration is broadband in nature, but a standard vibro-acoustic method was employed to demonstrate the correlation of analytical result with the experimental data in low and mid frequency range. This analytical method was successfully implemented on the center floor console NVH performance analysis and validated by using numerical simulations for accuracy.