Structural damage detection using rate of total energy

This paper presents a new system identification method called Damage Identification based on Total Energy Rate (DITER) to detect defects in structures. The proposed method employs an element-wise, time domain-based approach. Identification of elemental structural properties is performed through least squares optimization of an objective function created from the rate of total energy of the targeted elements. Using the total energy rate allows for a significant simplification in creating the objective function as compared to previous approaches that rely on equations of motion. Moreover, introduction of boundary elements' contribution in the derived objective functions makes the method flexible. As a result, it can be applied either to the whole structure or to any specific portion of the structure. In this novel approach, DITER converts displacement data into total displacement, measured from the undeformed configuration of the structure, by introducing static deflection correction terms. Thus, the proposed method is robust against static deflection variation and eliminates uncertainties in the initial displacement values. Numerical verification of the DITER method was performed on a two-span beam sample. Based on the results, DITER can be used as an efficient tool for nondestructive damage detection in existing structures.