A Novel Method for Bending Stiffness of Umbilical Based on Nonlinear Large Deformation Theory

In this paper a novel method is introduced to test the bending stiffness of umbilical. The four point bending test is studied both theoretically and experimentally. The nonlinear deflection model has been established because of large deformation. Half of the umbilical can be considered as a cantilever beam. By applying MATLAB optimization toolbox, we deal with differential equations with a nonlinear term pretty fast. Finally, an automatic testing system was designed to test the bending stiffness, which allows us to experimentally study the deflections of umbilical by means of a series of measurements.