Abstract:
Beam and plates in existence of crack is vulnerable to failure reckoning on the different mode of vibration. The natural frequency of the beams and plates and the superposition of periodic force acting on beams and plates form resonance which is the main cause of failure. It is crucial to find out natural frequency to remain aware about resonance that occurs due to periodic load. In this research work, we have used "Solidworks" software to design beams and plates without and with different types of cracks like slit crack, triangular crack, angular crack, semi-circular crack etc. Afterwards, we have used "ANSYS" simulation software to find the natural frequency and mode shapes of cracked and Non-cracked beams and plates for first six modes through modal analysis and made a through investigation of the vibrational behavior of different modes and mode shapes and made different comparison which can be used as one of the criteria for identification of cracks on beams and plates. The analysis has been extended to evaluate the effect of mesh refinement and crack opening size. For cracked beam, analysis is performed for various crack location and crack depth. In our work, we have observed that due to existence of crack, natural frequency changes. The amount of change varies depending on crack location, depth and crack opening size. Furthermore, we used harmonic analysis to find the deflection curves which can be used as one of the other criteria for crack identification.
Description:
Supervised by
Dr. Md. Zahid Hossain,
Professor,
Department of Mechanical and Production Engineering (MPE),
Islamic University of Technology (IUT),
Board Bazar, Gazipur-1704, Bangladesh