What is the difference between Operating Deflection Shapes (ODS) and Operational Modal Analysis (OMA)?

ODS = Motion of structure vibrating naturally (for example bridge vibration) or when excited by an unknown force (for example generator vibration).¬†Prosig’s Structural Animation software performs ODS analysis.

OMA = Modal Analysis
Prosig’s Modal Analysis software performs OMA. (more…)

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Read more about the article A Simple Frequency Response Function
Figure 5: H1(f)

A Simple Frequency Response Function

The following article will attempt to explain the basic theory of the frequency response function (FRF). This basic theory will then be used to calculate the frequency response function between two points on a structure using an accelerometer to measure the response and a force gauge hammer to measure the excitation.

Fundamentally a FRF is a mathematical representation of the relationship between the input and the output of a system.

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