Multi-Reference Mode Indicators

As part of the Multi-Reference Modal Analysis option, both Multi-Reference CMIFs (Complex Mode Indicator Functions) and Multi-Reference MMIFs (Multivariate Mode Indicator Functions) are added to the Mode Indicator methods list on the Mode Indicator tab.

A peak at or near the same frequency in two or more Multi-Reference Indicator curves indicates closely coupled modes or repeated roots.

CMIFs Indicating Two Closely Coupled Modes Near 200 Hz.

Multi-Reference CMIF

The Multi-Reference CMIF curves are calculated by performing a singular value decomposition of multi-reference FRF data, resulting in a separate CMIF curve for each reference.

Each peak on each CMIF curve is an indication of a resonance.

Multi-Reference MMIF

The Multi-Reference MMIF curves are calculated by performing an eigensolution of multi-reference FRF data, resulting in a separate MMIF curve for each reference.

Each peak (or valley) on each MMIF curve is an indication of a resonance.

Modal Participation Factors

The Multi-Reference CMIF & MMIF calculations also provide Modal Participation Factor curves for each reference of FRF data.

Modal participation factors are used to weight each reference of data during Multi-Reference curve fitting.