A GLANCE TO A MODE SHAPE BASED DAMAGE DETECTION TECHNIQUE
Damage in a structure is a local perturbation of its physical characteristics, i.e. its stiffness, mass and/or damping. Consequently, damage alters dynamic characteristics of the structure such as natural frequencies, damping value and mode shapes associated with each natural frequency. This is the base of vibration based structural health monitoring techniques. In this paper characteristics of mode shapes are investigated for identifying the location of damage in a beam structure. Cantilevered beam model is investigated numerically by use of finite element method. Slope and curvature of displacement mode shapes differences (between intact and damaged structure) were calculated using a central difference approximation. The results have shown that changes in the mode shape characteristics are good indicator of damage location and severity, and hence can be used to detect damage in a structure.