UMFPack Solver Error with Large Model

[hossein.bazeghi]

Dear STKO Team,
I modeled a 50-story high-rise building with flexible slabs.
The model is fully linear elastic, using elastic beam-column and elastic membrane plate sections with ASDShellT3 elements for shearwalls and slabs.

I tested the model with mesh sizes of 0.5m, 1.0m and 2.0m using both MUMPS and UMFPack. With MUMPS, all mesh sizes ran successfully without errors. However, with UMFPack, only 2m mesh size completed. the 0.5 and 1m mesh sizes give following errors:

Code: Select all

WARNING: numeric analysis returns -1 -- Umfpackgenlinsolver::solve
WARNING Linear::solveCurrentStep() - the LinearSOE failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 0.1
OpenSees > analyze failed, returned: -3 error flag

I double check my model geometry and there are no modeling errors in edges or faces connections. I tested the model using MUMPS solver with a single partition to see whether the issue was related to single CPU core limiations, and the analysis was progressing smoothly.

In another try, I divided the model into two sections, and ran each section independently with UMFPack, I could run it with mesh size 1m.

For the 1m mesh size, the model has:
Nodes: 141,329
Elements: 337,921

Questions:
1- Is this a known limitation of UMFPack for large models with high degrees of freedom, particularly those with flexible slabs?

2- Are there recommended methods or workflows for doing modal analysis on large buildings with flexible slabs at finer mesh size?

I appreciate your expertise and look forward to your recommendations.
Thank you for your time and assistance.

Hossein

[STKO Team]

MUMPS is generally better. But 100k nodes is not that much to create issues. If you share your model we can have a look