Fatigue Analysis of Flexible Riser

In order to predict the fatigue life of the flexible pipe effectively, it is necessary to establish a reasonable fatigue analysis model of the flexible pipe to provide the theoretical basis for the fatigue design of the flexible pipe. In this chapter, the nonlinear finite element software OrcaFlex is used to establish the global model of the flexible riser. In order to calculate the fatigue stress, the load model of the flexible pipe is divided into axisymmetric load and bending load. There are several ways to count the random fatigue load: peak counting method, cross-mean peak counting method, cross-level counting method, range counting method, and rain flow counting method. The rain flow counting method has a certain mechanical concept as a well-known counting method. In the fatigue analysis, the median S-N curve is generally used. Fatigue life analysis is a key factor in the fatigue design of flexible pipe.