Author : R. R. Das , A. Chakraborty , A. Guchhait and A. Singla

Three dimensional finite element analyses of laminated FRP composite made cylindrical shell structures along with interlaminar through-the-thickness cracks have been carried out. The developed FEM based modelling and simulation technique has been yielding results in close agreement with literature. Interlaminar cracks of similar sizes have been considered at edge and internal locations in order to study their effect on natural frequency of vibration of the cantilevered cylindrical composite shell structure. Cracks have been simulated in different locations from the clamped towards the free edge in order to study their effect on free vibration of the laminated shell structure. Interlaminar cracks have been observed to be reducing the natural frequency of vibration of the shell structures to a great extent, hence affecting the stiffness of the structure. However, for similar damage size and locations, internally-cracked composite cylindrical shells are comparatively stiffer than the edge-cracked cylindrical shell structures. Both the edge and internal cracks have been seen to be affecting the stiffness of the shell structure to a great extent through reducing the frequency of vibration, as they are close to the clamped edge. Composite shell structures with cracks towards the free edge have been comparatively safe as they marginally affect the frequency of vibration.

Keywords: Cylindrical shell structure, FEM, Laminated FRP composite, Free vibration, Interlaminar cracks. Natural frequency of vibration.

Article published in International Conference on Advances in Mechanical Sciences 2014, Special Issue-2 (Feb 2014)