Vibration behaviour of aluminium alloy beam with transverse cracks.

Cracks in engineering structures affect the dynamic characteristics and leads to failure of beam structures over a period of time. The crack will propagate due to vibration characteristics and the resultant fatigue in the beam structures. This paper focuses on a cantilever beam subjected cracks of different depth and its location under free vibration. The effect of such vibrations and crack are analyzed. Different aluminium alloys which find modern application in areas like aerospace, automobile, marine, construction industry etc. are considered for analysis. The change in modal shape and natural frequency of the beam structure due to crack under free vibration analysis is carried out by changing the crack location, crack depth and also the material properties by Finite Element Method (FEM) using ANSYS software. The natural frequency of the beams under test comprising of different Aluminium alloys is compared for various location and depth of crack. The modal shape of the free vibration analysis of the Aluminium alloy beam shows that the crack brings down the natural frequency level and it gets further reduced when the crack depth increases. [ABSTRACT FROM AUTHOR]