Damping properties and NVH Modal Analysis Results of Carbon Fiber Composite Vehicle Components 2017-01-0500
With the continuing challenges of future fuel economy targets carbon fiber composite materials are one facet of a lightweighting strategy to enable reduced fuel consumption. In general, use of lightweight materials such as carbon fiber composites in vehicle design generates vehicle NVH performance degradation. To address this potential issue at the design phase, there is a need to develop correlated CAE models for carbon fiber vehicle parts to evaluate the NVH impact of carbon fiber composite material use in vehicle design.
To develop correlated CAE models for lightweight vehicle design with the use of carbon fiber composite vehicle body parts, an experimental study was conducted to determine the material and NVH characteristics of the carbon fiber composite materials.
In this paper, the damping properties and NVH modal analysis results for structural carbon fiber thermoset composite panels and body parts (B-pillar upper insert and B-pillar lower insert) is presented. NVH modal analysis results include modes (natural frequencies), mode shapes, and modal damping. Damping properties of the carbon fiber composite parts are measured with a laser vibrometer up to a frequency of 1000 Hz. NVH CAE simulation results for B-pillar upper insert correlates well with the test data. Sound transmission loss test results for the a few carbon fiber composite panels are presented to highlight the high frequency NVH characteristics of carbon fiber composite material.
Average damping loss factor of the carbon fiber composite parts is approximately 1%. Even though carbon fiber composite material damping loss factor is five times greater than that of steel, it is significantly less than laminated sandwich steel which has a damping loss factor of approximately 25% .
Initial findings of the NVH performance impact of thermoset carbon fiber composite material use in vehicle design are also discussed.