Free vibration analysis of circular and annular thin plates based on crack characteristics
Can Gönenli, Oğuzhan Daş
Abstract
This study presents the effect of vertical and horizontal oriented cracks on free vibration response for circular and annular thin plates. To investigate the dynamic behavior of the damaged circular structures the cracks are modeled separately considering horizontal/vertical orientations, ten different locations, and four crack sizes. For annular thin plates, vertical and horizontal oriented cracks are placed in the middle between the outer and inner edges to investigate the effect of crack directions. The first five resonant frequencies, and the corresponding mode shapes of the cracked circular and annular plates, are obtained by employing the Finite Element Method. The free vibration analyses are conducted considering clamped boundary conditions for circular plates and clamped-clamped, clamped-free, and free-clamped boundary conditions for annular plates. The results are presented and interpreted considering the differences in the non-dimensional frequencies and the mode shapes of those structures. According to the findings, it is seen that depending on its location and size, a crack can change the mode shapes by accumulating the bending regions around it. Besides, a crack may also change the number of bending regions that occurred in the mode shapes of the circular or annular structures.