Door Seal Behavior Prediction and Enhancement in Performance Using Digital Simulation

Automotive door seal has an important function which is used extensively where interior of the vehicle is sealed from the environment. It must be functional and cohesive with the body design of the vehicle. Poor door seal system design will cause water leakage, wind noise, hard opening or closing of doors, gap and flushness issue which impair customer’s satisfaction of the vehicle. Moreover, improper design of seal can lead to difficulty in installation of door seal on body panel. The design prudence and manufacturing process are important aspect for the functionality and performance of sealing system. However, the door sealing system involves many design and manufacturing variables. At the early design stage, it is difficult to quantify the effect of each of the multiple design variables. As there are no physical prototypes during rubber profile beading-out stages, engineers need to carry out non-linear numerical simulations that involve complex phenomena as well as static and dynamic loads for door seal. This paper presents a digital simulation design tool based on FEM, basic governing laws and incompressibility constraints. Door seal was analyzed for compression load deflection (CLD) behavior using nonlinear finite element analysis in MSC Marc. The analysis results provided some major parameters, such as seal deformation, contact pressure and contact length of seal, which would influence the functionality and performance of the door sealing system. The analysis results have been compared with available test data, and very good correlation was obtained. The analysis also evaluated the influence of manufacturing deviations. With the results obtained, the relationship between the major parameters could be established and used as a tool to derive better sealing system design early stage. Eventually, this method is capable of predicting water leakage, wind noise and hard to open/close problems caused by either product design or manufacturing process.