High Mileage Squeak and Rattle Robustness Assessment for Super Duty Cab Weight Reduction Using High Strength Steel and Adhesive Bonding

Squeak and rattle is one of the major concerns in vehicle design for customer satisfaction. Traditionally, squeak and rattle problems are found and fixed at a very late design stage due to lack of up-front CAE prevention and prediction tools. An earlier research work conducted at Ford reveals a correlation between the vehicle overall squeak and rattle performance and the diagonal distortions of body closure openings under a static torsional load. This finding makes it possible to assess squeak and rattle performance implications between different body designs using body-in-prime (B-I-P) and vehicle low frequency noise vibration and harshness (NVH) CAE models at a very early design stage. This paper presents an application of this squeak and rattle assessment method for a design feasibility study concerning a cab structure of a super duty truck for weight reduction using high strength steel and adhesive bonding. The study indicates that downgaging and substitution of mild steel with high strength steel combined with adhesive bonding in selected areas of a cab structure can achieve 12.7 Kg (4% of B-I-P) weight reduction without tooling changes while maintaining high mileage squeak and rattle performance of the baseline vehicle.