Vibration Analysis of Cracked Composite Plate

Abstract

Composite materials are widely used in different arenas such as aircraft, naval and automobiles. Main motive behind that is the distinctive property of weight reduction, which is important for greater speeds, improved payloads and efficient fuel consumption. Various damages like cracks or delamination are inevitable during service period. They may be due to impact load, chemical decay or change in temperature or pressure conditions. It has been experimentally proved that confined damage in a structure causes the reduction in local structural stiffness, resulting in deviations in dynamic performance of the structure. Additional resonance or crack proliferation induce large displacements resulting in the failure of the structure. In this study, efforts have been made to determine the natural frequency of vibration of composite plate in different boundary conditions and the multiple parameters of crack have been varied and the results have been established. The tests on composite plate is done experimentally to find natural frequency using FFT analyser and the results are validated using ANSYS. The work is done with varying crack parameters like depth, length and orientation. The frequency decreases with increase in crack dimensions and decreases with increasing orientations. For different boundary conditions, frequency increases with decreasing degrees of freedom. This will help in designing structures resistant to earthquakes and other disasters, given that the resonance frequency is known earlier. It will help in building a safe structure and will prolong its life for many years.