Line data: Properties report

The line properties report is available from the popup menu on the data form.

Summary page

Note:

The properties report only accounts for nominal contents density. For the uniform contents method, this is the same as the actual density used in the calculation; however, this may not be the case for the other contents methods, which choose representative values when reporting the nominal contents density. In the case of the tabular contents method, the nominal contents density is a user data item.

Total length

The sum of all the section lengths.

Total weight excluding contents, total weight including nominal contents

The force due to gravity acting on the mass of the entire line. The weight of any attachments is excluded.

Total buoyancy

The weight of water displaced by the entire line's volume. The buoyancy of any attachments is excluded. The value is calculated based on a nominal water density.

Total submerged weight including nominal contents

Calculated as total weight including nominal contents $-$ total buoyancy.

Total mass excluding contents, total mass including nominal contents

The mass of the entire line, excluding the mass of any attachments.

Total displaced mass

The mass of water displaced by the entire line's volume. The volume of any attachments is excluded. The value is calculated based on a nominal water density.

Total submerged mass including nominal contents

Calculated as total mass including nominal contents $-$ total displaced mass.

Statics force accuracy, statics moment accuracy

Static analysis finds an equilibrium configuration – that is, a set of node positions for which the resultant force and moment on each node is zero. We refer to the resultant force and moment as the out-of-balance load. Because computers have finite numerical precision the static analysis cannot always find a configuration where the out-of-balance load is exactly zero. OrcaFlex accepts a position as a static equilibrium position if the largest out-of-balance load component is less than the statics accuracy.

The statics force accuracy is $\textit{tol} \times |\vec{f}_\textrm{char}|$ and the statics moment accuracy $\textit{tol} \times |\vec{m}_\textrm{char}|$, where $\textit{tol}$ is the whole system statics tolerance and the characteristic force, $\vec{f}_\textrm{char}$, and characteristic moment, $\vec{m}_\textrm{char}$, are calculated internally based on the forces and moments applied by coupled objects. Reducing this tolerance value will give a more accurate static equilibrium position, but will take more iterations. OrcaFlex may not be able to achieve the tolerance specified if it is too small, since the computer has limited numerical precision.

Statics moment accuracy is only reported if torsion is included

Details page

This contains a spreadsheet with the following information:

The values reported on the summary page, as described above.
Properties for each line type used by the line: weight, buoyancy, submerged weight etc.
Properties for each section of the line. This table includes details of segmentation, structure, hydrodynamics, contact and friction. When the section's line type uses a profiled diameter the properties are reported for each segment in that section.

If the line uses a P-y model then a page of detailed output is included which describes how the P-y model data have been interpreted.

If the line uses axial static-dynamic stiffness then a page is included which tabulates the axial stiffnesses used in statics and in dynamics.

Compound page

This page contains the compound object properties report for all nodes of the line.

The reported compound properties are based on an assumption that the nodes move as a single rigid body. No attempt is made by OrcaFlex to verify whether or not that assumption is valid. Therefore, this report is only useful for lines used to model structures such as spool pieces, rigid jumpers, etc.