This update contains a new convergence methodology for Structural Analysis of structures.
First and very significant, is that the new Catenary Cable Elements we introduced in earlier updates are now fully integrated into the structural analysis process. What this means is that during nonlinear analysis process, these elements will provide both the changing loads and changing stiffness factors. The end result for end users is a much shorter analysis time and more accurate results in some cases. Users may have noticed some structures taking up to 397 iterations to converge on a solution. Many examples we tested now take fewer than 10.
We also introduced a new methodology for arriving at the final converged results. We have noticed some scenarios when dealing with poles near their stability point, and also some with slack guys, that could not be solved; resulting in Quick Pole returning its belief that they are unstable. The new methodology for Quick Pole is to use Adaptive Load Control to better control convergence near stability points and when guys go slack or taut.
The impact to End Users is that some previous unstable poles may now come back as stable; with far fewer iterations as well.
To support these changes, the Analysis Convergence and Nodal Force Summary reports have been reworked. Also, when unstable poles are discovered, the analysis messages will include a note describing how close to this stability point this pole is, expressed as the percentage of assumed loads that could be applied before instability occurs.