Current Revision posted to RAM | STAAD Wiki by Steve Crabtree on 6/13/2016 5:41:53 PM
| Applies To | |||
| Product(s): | STAAD.Pro | ||
| Version(s): | All | ||
| Area: | Analysis | ||
| Subarea: | Instability and Zero Stiffness | ||
| Original Author: | Bentley Technical Support Group | ||
- I tried to model a concrete foundation using solid elements, basically following the approach described in example 24 of the examples manual. However, I got this warning stating "more than 12 DOF with zero stiffness". Can anyone please advise me what are the technical reasons for this and how I can possibly handle this warning?
- When we generate the spring supports for a raft foundation using the command "list-of-joints Elastic mat Dir YONLY SUB 10000" we get instability warnings in FX, FZ and MY directions at certain joints. Why?
- I have analyzed a structure and find that there are instability messages in the .anl (output) file
- If there are instability messages, does it mean my analysis results may be unsatisfactory?
- If there are instability messages, are there any simple checks to verify whether my analysis results are satisfactory?
- What does a zero stiffness warning message in the STAAD output file mean?
See Also
RAM Instability In Finite Element Analysis
Structural Product TechNotes And FAQs
Tags: FAQs, SELECTservices, STAADPro, Instability, zero stiffness