Vol.20, No.1, 2020, pp. 37–44
UDC:

Structural health monitoring (SHM) is a technique used for evaluating the condition of a structure during its service life. Damage in a structure changes its geometric properties, which in turn affects its modal parameters and hence these modal parameters are helpful in damage detection. In this study, three steel beams, a plate beam, an I-section beam, and a channel section beam with boundary conditions as a cantilever and fixed at both ends are considered. Damage is simulated by reducing the element stiffness, and such damages are created at different locations in the beam resulting in single and multiple damage conditions. For the damage detection technique, modal parameters, such as frequency and mode shape for the first five modes have been extracted using a finite element (FE) analysis based software ANSYS. A frequency-based method is adopted for damage identification and damage localization is carried out by the Mode Shape Curvature Square (MSCS), a damage index formulated from mode shape. Moreover, the MSCS approach performed well in identifying multiple damages in the structure. The results obtained exemplify the optimum number of modes to be considered for locating multi-damage effectively in symmetrical and unsymmetrical section.

Keywords: steel beams, multiple damage, damage detection, damage localization, mode shape curvature squares