抽象的

Theoretical and Numerical Vibration Study of Continuous Beam with Crack Size and Location Effect

Dr. Muhannad Al-Waily

In this research the natural frequency of a cracked beam with different supported, simply and clamped beam, is investigated analytically and numerically by finite element method with using of ANSYS program ver. 14 with different crack depth and location effect and the results are compared. The analytical results of the effect of a crack in a continuous beam are calculated the equivalent stiffness, EI, for a rectangular beam to involve an exponential function with depth and location of crack effect, with solution of assuming equivalent stiffness beam (EI) by using of Fourier series method. And, The beam materials studied are low carbon steel, Alloys Aluminium, and Bronze materials with different beam length and depth. A comparison made between analytical results from theoretical solution of general equation of motion of beam with crack effect with numerical by ANSYS results, where the biggest error percentage is about (1.8 %). Also it is found that the frequency of beam when the crack is in the middle position is less than the frequency with crack near the end position and the natural frequency of beam decreasing with increasing of crack depth due to decreasing of beam stiffness at any location of crack in beam.