Module 07
Finite-element building blocks
Freedoms, elements, restraints, releases and offsets — the five things you actually set, and what each one does to the answer.
What this module covers
- Count the degrees of freedom a model has and say what each one means
- Choose an element family from the outputs the question needs
- Predict what a joint between two families will and will not transfer
- Distinguish a restraint from a release, and say which belongs where
- Compute what an end release does to the moments and the deflection
- Explain why a rigid offset adds exactly V·e to the supporting member
Lessons
What a degree of freedom is, what each element family carries, and what happens where two families meet.
Start lesson →How the model is held to the world, and what happens inside it — with the moments and deflections for every case.
Start lesson →The rigid arm between a node and the member it actually connects to, and the moment it carries.
Start lesson →
Module checkpoint
Check what you have taken in
3 questions
Question 1
Why does a beam connected to a solid mesh at one node transfer no moment?
Question 2
A 10 m span carries 15 kN/m. What is the midspan moment if both ends are fully fixed?
Question 3
A beam's end shear is 64.89 kN and it frames into a column at an eccentricity of 0.30 m. The beam's own end moment is 44.99 kN·m. What moment does the column top see?