The Power Injection Method for Vibration Damping Determination of Body Panels with Applied Damping Treatments and Trim

The use of the Power Injection method for measurement of loss factors of complex panels with different trim systems is described. The basic theory is reviewed including the use of frequency response function measurements instead of direct measurement of input power and mean square response. The fundamental errors are presented. Practical considerations for reliable results are discussed and examplified. Examples of loss factor measurements on trimmed automotive panels are included.