A guide to troubleshooting your structural model if it is not solving
There are a wide range of reasons why your structural analysis model will fail to load. There are a number of basic list of errors such as Add a Support, Add Loads and Add a member. But what happens if you have your model built but but it is still not solving? SkyCiv has put together a guide of how to troubleshoot your model.
Does your model have cables?
Cables use non-linear analysis that require convergence to solve successfully. This convergence can cause issues and prevent the solver from completing.
What to try: Here is a guide on things to check for if your cable analysis is failing to solve.
Have you changed your member end fixities?
It is important to be aware that changing member end fixities from anything different to FFFFFF (to model things like pinned connections, roller connections, truss members etc..) can affect the stability of the structure. If a structure is inadequately connected, it will be unstable and the solve will fail.
What to try: change all your members to fully fixed FFFFFF (you can do this quickly by using CTRL + A (select all) then multi-edit the members by clicking Members on the left input). Need more help understanding fixities? Try our article on restraint codes and member end fixities (with video).
Are your supports fully fixed?
Very similar to the above point on member end fixities. If you have changed any of your support fixities to anything different to your typical fixities (FFFFFF, FFFFFR, FRFFFR), it may cause issues in the model. Examples include, FRFRRR
What to try: change all your supports to fully fixed FFFFFF (you can do this quickly by using CTRL + A (select all) then multi-edit the supports by clicking Supports on the left input).
Are you using Member offsets?
Member offsets create small rigid members between the node and the end of member. These can conflict with member end fixities and support fixities, so it’s a good idea to check if this is causing the issue.
What to try: remove all offsets in members and try to solve (use the datasheet or multi-edit to do this quickly and easily)