Module 08
Modelling structural systems
Trusses, frames, floors and cores — the usual model for each, its usual failure, and the hand check that catches it.
What this module covers
- Say what the pin-jointed truss idealisation gets right and what it omits
- Sweep a connection from pinned to rigid and locate where the change actually happens
- Compare four models of the same floor panel against an exact plate solution
- Decide when a core needs more than a stick model
- Name the hand calculation that validates each system
- Recognise a peak that is a singularity rather than a result
Lessons
What the pin-jointed idealisation omits, and where a connection stops being pinned.
Start lesson →Four models of one floor panel against the exact answer — and when a core needs more than a stick.
Start lesson →One hand check per system — the only kind that actually gets done.
Start lesson →
Module checkpoint
Check what you have taken in
3 questions
Question 1
A shell model of a flat slab reports a moment over a column that doubles each time the mesh is halved. What should be done?
Question 2
A portal's eaves moment is 135.8 kN·m and its beam carries 15 kN/m over 12 m. What is the midspan sagging moment?
Question 3
A 5 m × 5 m panel is modelled as a one-way strip, giving 31.25 kN·m/m against an exact 11.05. If the reinforcement is proportional to moment, by what factor is the short-direction steel over-provided?