You may find this useful:

https://issuu.com/journals.ats/docs/ijsea04031009

 tank u sir.., can i get little details abt this

Dear Merlin Freeda,

if you have to detect damage on framed structures, you could use a methodology based on the modal curvature evaluation (the proposed methodology works into the time-frequency domain). You can find a simpe description in the following papers. If you have any questions, do not esitate to contact me.

Sincerely,

Rocco Ditommaso

Article Analysis of non-stationary structural systems by using a ban...

Article Automatic evaluation of the fundamental frequency variations...

Article Damage detection on framed structures: modal curvature evalu...