<< Click to Display Table of Contents >> Navigation:  Flexcom > Data Inputs > $LOAD CASE >
*NO PIP SLIDING

Purpose

To disable the interchangeable nature of sliding pipe-in-pipe connections.

Theory

Refer to Sliding Connections for further information on this feature.

Keyword Format

This keyword does not contain any further data.

Table Input

Notes

(a)The default is to No. This is the recommended setting for the majority of analyses.

(b)To disable the interchangeable nature of sliding pipe-in-pipe connections, select Yes. In certain circumstances, it may be desirable to allow the software to initially determine appropriate connections between an inner and outer pipe, and to subsequently treat these connections as Standard Connections. For example, when setting up a work-over riser model, the initial set-down of the inner tubing can make it very difficult to manually identify the required nodal connections in advance of the initial static analysis. Designating the connections as Sliding allows the program to automatically determine the optimal set of pipe-in-pipe connections, minimising effort on the part of the user. While there may be significant relative axial motion between the initial model definition and the converged static solution, there is comparatively little axial motion during the actual simulation itself (e.g. when the model is subjected to wave loading). Invoking the *NO PIP SLIDING keyword in subsequent restart analyses thereby ensures computational efficiency (any overhead associated with the monitoring of nodal locations is eliminated), and can also provide enhanced numerical stability (connectivity of the finite element model remains consistent throughout the simulation).