IDENTIFICATION OF DAMAGE LOCATIONS IN STEEL BEAMS BASED ON CHANGES IN NATURAL FREQUENCIES

Abstract

When damage occurs in a structure, it results in changes to its dynamic characteristics including natural frequencies, mode shapes, and damping ratios, compared to an undamaged structure. Based on this principle, several methods have been researched and applied to identify damaged regions in structures. In this article, a cantilever steel beam with constant cross-section is studied by dividing it into regions, where each region is classified based on the first four normalized natural frequencies. The damaged region is identified by classifying the normalized frequencies of the structure through the ratio of the natural frequency of the damaged beam to that of the undamaged beam. A simulation is conducted using SAP2000 for both the intact and damaged cantilever beam to determine its natural frequencies, serving as a basis for identifying the damage location and severity. The identified damage region matches the assumed location and is independent of damage severity. The research results demonstrate that changes in natural frequencies can be utilized to identify damage on cantilever beam structures, providing a basis for the application in detecting damage locations in more complex structures and real-world constructions.