Crack Detection in Structures Using Modal Strain Energy and Frequency

In this paper a new method for crack detection in structures based on first three mode frequencies and modal strain energies using least square support vector machine has been proposed. Since the mode shape vectors are equivalent to nodal displacements of a vibrating structure, therefore in each element of the structure strain energy is stored. The strain energy of a structure due to mode shape vector are usually referred to as modal strain energy (MSE) and can be considered as a valuable parameter for crack identification. Also, change of natural frequencies is effective, inexpensive, and fast tool for non-destructive testing. So, the proposed method uses the first three natural frequencies and modal strain energies as the input parameters and crack states as output to train the least squares support vector machine model.