Equivalent thickness concept for estimating maximum load of complex cracked pipes using through-wall cracked pipe solutions

This paper proposed a concept of an equivalent through-wall cracked pipe to evaluate the maximum bending load of a complex cracked pipe. The outer radius and through-wall crack length of the equivalent through-wall cracked pipe are assumed to be the same as the complex cracked pipe, and thus the equivalent pipe thickness is the only variable to be found. Systematic FE damage analysis shows that the equivalent pipe thickness depends linearly on the relative surface crack depth of the complex crack, regardless of materials. Elastic-plastic fracture mechanics analysis for existing complex cracked pipe test data using the proposed concept shows good agreement between predicted maximum loads with experimental data, confirming that the maximum bending load of a complex cracked pipe can be determined using existing fracture mechanics analysis methods for through-wall cracked pipes.