Dynamic Behavior of Damaged Beam Subjected To Moving Mass

Abstract

The present work emphasizes the dynamic response of cracked cantilever beam subjected to a moving mass. The cracks are located at different positions of the beam with random crack depths. The dynamic behavior of the damaged cantilever beam has been computed for different combinations of crack depth, crack location, moving mass magnitude and moving mass velocity.
The work done, thus find the dynamic response of different structures that are subjected to moving masses and vehicles in their lifetime. In addition, this generates a data base, which can be further used to predict the crack location and severity using Artificial Intelligence techniques.
The response of the end point of the beam with respect to different loading conditions and crack condition has been found out by employing theoretical analysis, Finite Element Analysis and Experimental Analysis. A numerical procedure of Duhamel‟s integral has been employed to find out the theoretical result. Modal Analysis and Transient Dynamic Analysis of ANSYS Workbench 15.0 is used to find out the response by Finite Element Analysis.
The results thus obtained from theoretical analysis and Finite Element Analysis is compared with the results from experimental analysis and they are found to be validating each other. It has been observed that with the increase of moving mass magnitude, the end point deflection of the beam also starts increasing. But with the increase of traversing speed, the end point deflection decreases. It‟s because at higher speed, the lower modes of the structure are not vibrated which are responsible for producing larger amplitude. Again the presence of the crack on the structure increases the beam deflection and reduces the natural frequencies as comparison to un-cracked beam.
The result from the analysis is very significant and helps to understand the dynamic response of different transporting structures which are subjected to moving loads or vehicles. Further the research work can be extended to more complex structures in defense, aerospace and transportation engineering after some modifications.