Free body diagrams are used in structural analysis to try to reduce the problem to its simplest description. Where does the load get applied and where does the load get reacted? Free body diagrams can be created for the overall assembly and for each component in that assembly – hence tracking the load path.

This seems like a straightforward procedure – but in fact, it is surprisingly easy to get things very wrong!

In this presentation, Tony shows a very early example from his stress office days and talks about an industrial example that had tragic consequences.