Systematic Approach for Optimizing Tailgate Stoppers and Its Location to Prevent Squeak and Rattle

Tailgate stoppers play vital role in exerting preload on the Tailgate latch mechanism and also restrict the relative motion of the Tailgate against vehicle Body in White (BIW). These stoppers act as over-slam dampeners and reduce the transmissibility of vibrations thereby reduce the risk of Squeaks & Rattles (S&R) noises. S&R noises from Tailgate are most annoying to the rear passengers in the vehicle and are recurring in nature. Preventing these issues during design is a challenging task. S&R risk simulations enable us to conduct virtual Design of Experiments (DOEs) and arrive at optimal solutions. This approach helps in reducing the cost of the design changes that are required in the physical prototype at the later stages of product development and save time. The risk evaluation in the simulations is based on the relative displacement at the interfaces of two components. These interfaces are represented by Evaluation Lines (E-Lines) which are nothing but a series of nodes at the interface locations. The Tailgate stoppers are modeled using a spring element with stiffness calculated from force deflection experiments. The variations due to the manufacturing process are addressed through the statistical analysis of tolerances provided for the design gaps. In this work, simulations are carried out using Squeak and Rattle Director (SnRD) on a Compact Utility Vehicle (CUV) Tailgate to optimize the stiffness, location and number of stoppers required to eliminate S&R noises.