• In Lab 6, you discovered one reason why trusses are used rather than beams

  • Some situations call for more depth than a beam can easily provide.

  • A truss allows a strong and stiff structure to be built from relatively small components.

• The problem also highlighted some important aspects of design

  • Design is a process of search within a constrained space.

  • Design is iterative and cyclic, not linear and direct.

  • Some things just don't work.

• The problem had good and bad points:
  • Good: Allows broad exploration of design space, focussing on behavior rather than calculation details.

  • Bad: The problem was pure model manipulation without any sense of a real structure and how it would be detailed for construction braced in three dimensions, or how the structure would look in an architectural context. It was a "stress invaders" video game.

  • Good: The problem allowed you to discover why trusses are used, and how to look carefully at the assumptions and constraints of a problem.

  • Bad: The constraints were very incomplete, since they did not include checking the strength of the members, particularly buckling.

  • Good: The problem offers an opportunity to show the value of back-of-an-envelope calculations to make decisions about overall form. We'll look at this.

A few solutions.

26 K

18 K

11.8 K

9.8 K

8.6 K

7.8 K