Is AutoPIPE software suitable for the analysis of subsea pipeline crossings?
AutoPIPE is limited to small displacement analysis and elastic pipe material. As long as these limitations are justified, you may use AutoPIPE for pipe stress analysis. Small displacement assumption implies that the pipe deflections will not severely affect computed forces and moments. For example if a simply supported horizontal beam of length L deflects L/4 at the mid span, this will be considered a large deflection since pipe weight is no longer supported by moment alone. Axial force or cable catenary action will contribute more to pipe resistance than moment in this case. AutoPIPE analysis for straight beam will show a zero axial force which is not correct if the vertical deflection is large.
In some cases the user may require a strain limit instead of stress allowable limit, AutoPIPE results will be conservative since we do not allow yielding of pipe material. A material nonlinear model may be required to justify larger deflections in this case.
Ultimately the client has to approve the use of AutoPIPE knowing the limitations over the program. Bentley's CAE development team is constantly updating the application with new enhancements and abilities. Please review the latest version of AutoPIPE for current capabilities and limitations.
Model Subsea (Underwater) Piping