Creating models
Describe the structure and let Dlubal CALC build it in your open RFEM.
Build a portal frame in RFEM: span 12 m, height 5 m, HEA 240 columns, IPE 400 rafter, pinned at the base. Then show me what you created.
Say what a drawing would say
The description that works is the one you would hand a colleague: system, spans, sections, material, supports, loads. Leave one of those out and you get a question rather than an assumption.
Continuous beam over three spans, 6 m each, IPE 330 in S235,
pinned at both ends and on the intermediate supports,
permanent load 8 kN/m and imposed 5 kN/m as separate load cases.
Support conditions are the field people leave out most often, and the one that changes the result most. If you do not say, you will be asked.
Check three things before calculating
The axis orientation. After creating geometry the assistant states whether Z points up or down and shows a coordinate with its sign. A mirrored model calculates happily and gives plausible nonsense.
The count. Ask what was created. Members, nodes, supports and load cases are quick to compare against what you described, and much quicker than reading results that came from the wrong structure.
The load cases. They are the second most common source of a wrong result: one combined case where you meant two separate ones changes everything downstream.
Rebuilding after a mistake
Say what is wrong and ask for a correction. The assistant works in the model that already exists rather than making a second one, which is what you want: a duplicate model with a slightly different name is how people end up calculating the wrong structure for an hour.
Example: "the rafter should be IPE 450, not IPE 400. Change it in place and tell me what else that affects."
Where to go next
- Running calculations once the model is right.
- RFEM troubleshooting when a build does not start.