Exactly a year since the previous update I have revised the 3DFrame-py spreadsheet with the addition of non-linear analysis options.

The new files can be downloaded from:

3DFrame-py.zip

Details of file installation, and required software are at:

3DFrame-py

Minor revisions to the installation files will be covered in the next post.

The new code allows for non-linear analysis for geometric effects and/or using moment-curvature tables for non-linear flexural effects.

Enter 0 or 1 in the appropriate column to exclude or include the non-linear analysis.

For moment-curvature non-linearity to be included, moment curvature tables must be added to the new Input3 sheet, and the table allocated to each property type added in the new “MomCurve Table” column on the right.

Note that:

• The non-linear analysis does not currently work with warping effects included. The warping code still works with the linear analysis option set.
• Code linking to the Numba just-in-time compiler needs more work. At present it works, but gives no performance improvement.

The non-linear code has been checked against Strand7 analyses for the frame below, with high axial loads applied to the horizontal members.

Vertical deflection results are shown below for the linear, non-linear geometry, and non-linear geometry and material effects. It can be seen there is a large increase in deflections due to non-linear effects, with good agreement between the Strand7 and 3DFrame results.

There was also a large increase in bending moments in the geometric non-linear analysis, with a small additional increase from moment-curvature effects. There was again close agreement between the Strand7 and 3DFrame results.