Experimental and Numerical Investigation of a Cracked Cantilever Beam for Damping Factor to Access its Applicability in the Crack Detection

Abstract

The cracks alter the physical and modal properties of the beam, i.e., stiffness, damping, natural frequency, and mode shapes, and, in turn, the dynamic response of the beam changes to a considerable extent. The condition monitoring of the beams is essential to avoid its catastrophic failure in applications. A basic criterion has been followed for modal parameters like natural frequencies, mode shapes, and stiffness for the possible crack detection. In contrast, damping as a dynamic property to represent structural damage has been limited due to the difficulties in measuring damping and analysis. Therefore, in this study, the effect of various possible crack profiles, i.e., V-shaped and U-shaped, on the applicability of using the damping criterion for determining the presence of damage in the cantilever structure was investigated. The damping loss factor for all the cracked cases of a cantilever beam was computed using ANSYS and experimental analysis. The numerical results of the damping loss factor were compared with experimental results. It was understood that the results were susceptible to the crack geometries changes.

Keywords

• effective mass
• dewesoft frf
• impact hammer
• v-shaped crack
• u-shaped crack
• structural health monitoring
• ansys
• torsional stiffness
• resonant amplitude