A SIMPLIFIED METHOD FOR NATURAL FREQUENCY ANALYSIS OF A MULTIPLE CRACKED BEAM

A new method for natural frequency analysis of beam with an arbitrary number of cracks is developed on the bases of the transfer matrix method and rotational spring model of crack. The resulted frequency equation of a multiple cracked beam is general with respect to the boundary conditions including the more realistic (elastic) end supports and can be constructed analytically by using symbolic codes. The procedure proposed is advanced by elimination of numerical computation of the high order determinant so that the computer time for calculating natural frequencies in consequence is significantly reduced. Numerical computation has been carried out to investigate the effect of each crack, the number of cracks and boundary conditions on the natural frequencies of a beam.