Browse Publications Technical Papers 2003-01-1566
2003-05-05

A Comparison Between Power Injection and Impulse Response Decay Methods for Estimating Frequency Averaged Loss Factors for SEA 2003-01-1566

Damping measurements on vehicle subsystems are rarely straightforward due to the complexity of the dynamic interaction of system joints, trim, and geometry. Various experimental techniques can be used for damping estimation, such as frequency domain modal analysis curve-fitting methods, time domain decay-rate methods, and other methods based on energy and wave propagation. Each method has its own set of advantages and drawbacks. This paper describes an analytical and an experimental comparison between two, widely used loss factor estimation techniques frequently used in Statistical Energy Analysis (SEA).
The single subsystem Power Injection Method (PIM) and the Impulse Response Decay Method (IRDM) were compared using analytical models of a variety of simulated simple spring-mass-damper systems. Frequency averaged loss factor values were estimated from both methods for comparison. The parameters of the analytical models were varied to study the effects of the total number of modes, amount of damping, location of modes within frequency bands, and the width of the frequency bands on loss factor estimation.
The analytical study showed that both methods give accurate loss factor values as long as one modal resonance is present in each frequency band and as long as the damping values remain realistic for linear systems. These analytical results were confirmed experimentally by measuring the loss factors of simple steel plates, with and without damping treatments applied.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 18% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Absorption Technique for Road Noise

2009-01-0020

View Details

JOURNAL ARTICLE

Vehicle NVH Analysis Using EFEA & EBEA Methods

2009-01-0766

View Details

TECHNICAL PAPER

Design and Development of the 2001 Michigan Tech FutureTruck, a Power-Split Hybrid Electric Vehicle

2002-01-1212

View Details

X