Browse Publications Technical Papers 2016-36-0430
2016-10-25

Operational Modal Analysis Using Durability Test Data 2016-36-0430

Operational modal analysis is when the modal properties are identified from measured responses only. The modal parameters are: mode shapes (the way the structure moves at a certain resonance frequency), natural frequencies and damping ratios. When modal identification is based on the measured response (output) only, things become more complicated: The excitation (input) is unknown and the measured response (output) is often noisy. In this study, the time domain Stochastic Subspace Identification - Unweighted Principal Components operational modal analysis was applied to the recorded dataset from the durability test conditions of a truck. Using the 40 minutes of road test accelerometer time history in three different road conditions, it was possible to identify the modal parameters and also compare with numerical modal analysis data. Both results presented good correlation. It is important to note that no specific instrumentation was mounted for modal analysis, and the truck was running under true boundary conditions, actual force and vibration levels and frequency range, testing is done in-situ using the natural excitation.

SAE MOBILUS

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

Access SAE MOBILUS »

Members save up to 43% off list price.
Login to see discount.
Special Offer: With TechSelect, you decide what SAE Technical Papers you need, when you need them, and how much you want to pay.
X