Stress intensity factor for cracked submarine pipeline with concrete cover

For the cracked submarine pipeline with concrete cover, a new method to estimate the stress intensity factor has been proposed based on the concept of the crack surface widening energy release rate. Unlike the classical crack extension energy release rate, the crack surface widening energy release rate can be expressed by the G*-integral and the elementary strength theory of materials for the submarine concrete-covered pipeline with the cracks. In present discussions, a series of solutions of the stress intensity factors in the closed form are derived for cracked pipeline. Analytical results show that the concrete layer covering the pipe is beneficial to the safety of the pipeline. The present method can also be applied to other form of submarine pipeline such as the cracked pipe-in-pipe pipeline. (c) 2006 Elsevier Ltd. All rights reserved.