عيب يابي ورقها از روي آناليز تغييرات در شكل هاي مودي

Damage identification from changes in vibration characteristics of structures is -the subject of many current researches. In this regard, several different methods, i.e. vibration frequency changes, mode shape changes, strain energy mode shape changes, and the wavelet. analysis, have been suggested. In this paper, these methods are applied to a 6 rectangular cracked plate. The vibrational characteristics of the plate are obtained, and . the results for different locations and sizes of the crack are studied. This comparison shows that the method of vibrational frequency changes has the least sensitivity to the presence of the damage, while the methods of the damage index changes and the wavelet analysis are most sensitive to the damage. The damage detection in all of the above mentioned methods except the wavelet analysis is done through detection of any changes in the vibrational characteristics before and after the introduction of the damage.