The Effect of Seal Stiffness on Door Chucking and Squeak and Rattle Performance

Traditionally, door seals are designed to achieve good wind noise performance, water leakage and door closing effort in a vehicle design and development process. However, very little is known concerning the effect of door seal design on vehicle squeak and rattle performance. An earlier research work at Ford indicates a strong correlation between the diagonal distortions of body closure openings (in a low frequency range 0 - 50 Hz) and overall squeak and rattle performance. Another research at Ford reveals that relative accelerations between door latch and striker in a low frequency region (0 - 50 Hz) correlate well with door chucking performance. The findings of this research work enable engineers to assess squeak and rattle and door chucking performance using vehicle low frequency NVH CAE models at a very early design stage. This paper is concerned with a sensitivity study of door chucking and squeak and rattle performance with respect to door seal stiffness using two performance metrics (diagonal distortions at closure openings and relative accelerations between latch & striker) mentioned above. It is found that door chucking performance improves with the increase of seal stiffness monotonically. Whereas overall squeak and rattle performance is dictated by match boxing modes of doors and liftgate that are in turn affected by seal stiffness. No special trend is observed in terms of squeak and rattle sensitivity with respect to seal stiffness.