Determination of crack location from changes in natural frequencies

Publisher Summary In this chapter, first the boundary integral equation method has been applied to the forward problem of calculation of natural frequencies of a cracked cantilever beam. Beams are the basic structural elements that are widely used in many branches of structural engineering. One of the problems that arises under the operating conditions is the crack occurrence, which may lead to a failure in the machines. To minimize the serious threat it is desirable to detect the existence and the location of the crack. Further in this chapter,a direct approach has been used for the inverse problem of determining a crack location. An algebraic equation, which relates the crack position to the crack flexibility, has been obtained in an explicit form. If the first three intact and corresponding damaged natural frequencies are known, by plotting the flexibility with the crack location the damage can be located accurately from the intersection of the three curves.