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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.

High mileage NVH performance is one of the major concerns in vehicle design for long term customer satisfaction. The current paper is concerned with performance analysis of high mileage vehicles which cover four automobile manufacturers and five vehicle families of the same weight class based on subjective evaluation data. The analysis includes the assessment of five vehicle families from the following aspects: overall and NVH performances, performance by individual attribute, degradation history of each vehicle family, performance variation within each vehicle family. Since the data are statistical in nature, statistical methods are employed, numerically and graphically, in the analysis. The performance categories which exhibit most degradation are identified. The analysis method presented in this paper is applicable to any high mileage vehicle fleet subjective data. The knowledge derived in the study can be used as a guideline in designing vehicles for high mileage NVH robustness.

High mileage NVH performance is one of the major concerns in vehicle design for long term customer satisfaction. Elastomeric components such as suspension bushings, engine mounts and tires function as vibration isolators in a vehicle. High mileage tends to cause the degradation of these components which in turn affects vehicle overall NVH performance. The present paper discusses the characteristics of bushing degradation based on laboratory bushing test data. Vehicle subjective evaluation and CAE modeling methods are used to develop a fundamental understanding of the effects of bushing degradation on vehicle NVH performance. The concept and analysis methodology are demonstrated using the front and rear suspension strut mounts and tire inputs which simulate road excitations but they are valid for other elastomeric components such as engine mounts and excitations. The knowledge derived in the study can be used as a generic guideline in designing vehicles for high mileage NVH robustness.