Dynamic Analysis of Multi-cracked Hollow Rectangular Beams

The hollow rectangular beams have wider applications in structural applications. The strength of the hollow beam depends upon various factors such as section thickness, end support, loading environment, etc. Out of which the structure integrity is one of the major factors that decides the stability of the hollow beam. Sometimes the integrity of the structure is altered due to the occurrence of cracks, holes etc. Hence the study of dynamic stability of the hollow beams keeps its own importance. Here, the modal response of the hollow rectangular aluminum beam with multiple cracks is investigated. Theoretical formulation for the beam with multiple cracks is concepted by an equivalent shear spring model. Finite element formulation is conducted by ANSYS 16.0. A portable modal testing module is fabricated and the fundamental frequencies of the cracked beam are determined experimentally. The outcomes are compared and validated. Further, the change of fundamental frequency to the change of crack locations, crack severities, crack severity to section thickness, and to the presence of multiple cracks (four cracks) is investigated and conclusions are drawn.