Experimental Modal Analysis

Vibration measurements and analysis

Experimental Modal Analysis

Experimental Modal Analysis (EMA) is an effective instrument for describing, understanding and modelling the dynamic behaviour of a structure.
It can be carried out both to determine the natural frequencies and mode shapes of a structure and to verify accuracy and calibrate a finite element model (FE). Also, the EMA can be used in order to make a troubleshooting vibration problems.

Thanks to the best specialized softwares, SINT can carry out the PRE-TEST analysis (in order to chose the best set-up measurement) and the CORRELATION analysis (for the comparison of the Finite element model with the experimental model).

SINT Technology can determine the main modal parameters:

Natural frequencies
Mode shapes
Damping

The validation of the modes is done using the following:

Modal Assurance Criterion (MAC)
Complexity tools
Modal Phase Collinearity (MPC)
Mean Phase Deviation (MPD)
Phase scatter

Some examples of the experimental modal analysis techniques that SINT Technology can use are:

Impulse excitation (instrumented hammer)
Controlled excitation (shaker)
Operational Modal Analysis (OMA)
Operational Deflection Shape (ODS)

Experimental Modal Analysis standards

ISO 7626-2

Vibration and shock – Experimental determination of mechanical mobility – Part 2: Measurements using single-point translation excitation with an attached vibration exciter

ISO 7626-5

Vibration and shock – Experimental determination of mechanical mobility – Part 5: Measurements using impact excitation with an exciter which is not attached to the structure