Abstract

We analyze a suspended pipe with the application to offshore pipelaying and suspended production risers. Basic equations from the planar theory of elastic rods are reduced to a second-order ordinary differential equation with special end conditions that is solved numerically. Dimensionless results are given for the maximum curvature in the sag portion of the pipe and the slope angle at the upper end of the pipe in the absence of hydrodynamic forces. Both a rigid and a compliant seafloor are treated. We find that tension is highly effective in limiting curvature. A equation is found for the applied tension at the upper end of the pipe. Our results are intended for preliminary design studies that can be followed by more sophisticated analyses.

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