Even though Vibration modes analysis is a critical element of a design it is often ignored. Structural elements like complex steel floor systems can be predominantly subjected to noticeable vibration. Natural vibration modes in structural works and mechanical support systems will cut down equipment life, Premature or unexpected failure may occur due to vibration modes this may result in hazardous situations. Potential for failure or damage due to rapid stress cycles of vibration can be assessed by detailed fatigue analysis.
Detailed seismic study also needs an understanding of the natural vibration modes of a system, because during seismic activity the large amount of energy acting on a system varies with frequency.
The fundamental vibration mode shapes and corresponding frequencies are resolved by detailed modal analysis. This can be comparatively simple for basic elements of a simple system and extremely complex when qualifying a complicated mechanical device or a complicated structure exposed to periodic loading. These systems necessitate exact determination of natural frequencies and mode shapes by means of techniques such as Finite Element Analysis.