Open Access

ARTICLE

Effects of Precise FRF Measurements for Frequency Based Substructuring

by Julie Harvie, Peter Avitabile

Structural Dynamics and Acoustic Systems Laboratory, University of Massachusetts Lowell One University Avenue Lowell, Massachusetts 01854
The author can be reached at: Peter_Avitabile@uml.edu.

Sound & Vibration 2018, 52(1), 3-7. https://doi.org/10.32604/sv.2018.03618

Abstract

Impedance modeling is often utilized to generate frequency response functions of an assembled system using modal characteristics of individual components. Sometimes slight inaccuracies are manifested in the characteristics of the components. Although those inaccuracies may seem minor in regards to the component for a traditional modal model, the inaccuracies can be amplified when impedance modeling is performed. Frequency based substructuring involves inversion of the frequency response functions and therefore requires considerable accuracy for the measurement, particularly in the area of anti-resonances.
For this study, some aspects of frequency based substructuring were explored, namely difficulties that might be encountered in experimental testing related to drive point measurements. The majority of studies were performed using analytical models to minimize contamination of data. The study focuses on connection point measurements where the actual location might be inaccessible due to physical constraints such as hardware, holes, etc. Hence the effect of introducing slight inaccuracies to the location of the drive point measurement was studied, along with other aspects related to the accuracy of the critical connection measurement.

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