Learning Forum

[Keyur Kanade]

What is a mode shape in context of vibration?

[prajput]

Consider a simple example of a guitar string. When you pluck a guitar string it may vibrate such that it forms a half sine wave when it vibrates (i.e. has only one crest in the center) or have a complete sine wave (i.e. has one crest and one trough along the length of the string) or have multiple sine waves on it. Each of these "forms" in which a string can vibrate are called mode shapes of vibration

[Karthik Remella]

To add to the above example, each of those mode shapes will occur when the string is vibrating at certain characteristic frequencies. E.g. mode 1 may occur when the string is vibrating at 2 Hz, mode 2 may occur when the string is vibrating at 4 Hz etc. These are the natural frequencies associated with those mode shapes.