Author(s)

N. Bassim

Abstract

Assessment of damage in materials and structures can be carried out by applying elements of both fracture mechanics and nondestructive testing. This is particularly important for determining the remaining life of structures subjected to cyclic or fatigue loading. In fatigue, the relationship defining the rate of crack growth dA / dN is given by the Paris law as dA / dN = a(∆K)b where A is the crack length, N is the number of cycles, a is a constant, K is the stress intensity factor and b is an exponent which has a value of about 3 for pearlitic steels and 4 for aluminum alloys. In the present research, we establish a similar relationship between elements of signals obtained from monitoring using nondestructive testing techniques, such as ultrasonics and acoustic emission. Signal characteristics include features of pattern

Keywords