The Chartership Forum

Structural Analysis Fundamentals / module 1

Structures, modelling and idealisation

What a structure has to do, the forms engineers use, and how a real structure becomes a model you can analyse.

What you will understand

  • Describe the job a structure has to do, and trace a load from where it lands to the ground
  • Recognise the common structural forms and what each is good at
  • Turn a physical structure into a reasonable first analytical model
  • Say what your model assumes, and what those assumptions leave out
  • Tell a determinate structure from an indeterminate one, and spot a mechanism

Lessons

  1. What a structure has to do

    Load paths, structural forms, and the journey from load to ground.

  2. From a real structure to a model

    Idealisation, assumptions, degrees of freedom and determinacy.

Module summary
  • A structure carries load safely to the ground without moving too much or falling down
  • Different forms carry load in different ways: beams bend, ties stretch, struts squash, arches and cables mostly work in one direction
  • Analysis is done on a model, not on the real thing — the model is a decision you make
  • Supports determine the reaction components; stability, internal releases and independent equilibrium equations determine whether equilibrium alone is sufficient
Teaching basis and review status

These are educational models and exercises. Check their assumptions before using the results. The full technical content and every diagram have not yet been independently verified.

Concrete and steel calculations retain their stated first-generation Eurocode teaching basis. Use the standards and amendments specified for your project; do not mix generations without an appropriate design basis.

Read the lesson register and outstanding review notes

Check your understanding

Check yourself

Which support gives exactly two reactions?

Check yourself

A stable, single-bay plane frame with rigid joints and no internal releases has 5 unknown reactions. What is its degree of static indeterminacy?

Check yourself

Why are trusses made of triangles?