Simulating the Static and Dynamic Response of an Automotive Weatherstrip Component 2011-01-1602

Understanding the resonant behavior of vehicle closures such as doors, hoods, trunks, and rear lift gates can be critical to achieve structure-borne noise, vibration, and harshness (NVH) performance requirements, particularly below 100Hz. Nearly all closure systems have elastomer weatherstrip components that create a viscoelastic boundary condition along a continuous line around its perimeter and is capable of influencing the resonant behavior of the closure system. This paper outlines an approach to simulate the static and dynamic characteristics of a closed-cell Ethylene Propylene Diene Monomer (EPDM) foam rubber weatherstrip component that is first subjected to a large-strain quasi-static preload with a small-strain sinusoidal dynamic load superimposed. An outline of a theoretical approach using “phi-functions” as developed by K.N. Morman Jr., and J.C. Nagtegaal [1] is introduced followed by a discussion of the material characterization that was done to construct a suitable elastomer material model for finite element analysis (FEA). Next, to validate the approach, the FEA and correlation of a simple extension specimen is presented followed by the analysis and correlation of a weatherstrip component with a complex cross sectional shape. It is observed that the static and/or dynamic response of the weatherstrip material and component can be dependent on several factors such as excitation frequency, large-strain preload, vibration amplitude, component geometry, and friction. Correlation between simulation and experimental results for dynamic stiffness and loss factor are in general agreement below 100Hz.