1. by Jaime R. Rico

2. In the design of a structure, it’s very important to achieve rigidity and stability DESIGN STRUCTURE RIGIDITYSTABILITY we must achieve

3. RIGIDITY A structure is rigid if it maintains its shape when a force is acting on it RIGID NON/RIGID

4. STABILITY A structure is stable if it doesn´t fall down or fall over when a force is acting on it STABLE UNSTABLE

5. STUDYING RIGIDITY All polygons distort, excepto uno. Which one?

6. TRIANGULATION GUSSET PLATES To achieve rigidity we use triangulation and gusset plates

7. DESIGN STRUCTURE RIGIDITYSTABILITY we need by means of TRIANGULATIONGUSSETS WIDER BASE LOWER C.o.G. by means of

8. TRIANGULATION

11. GUSSET PLATES Are metal * plates used to strengthen a joint

14. Exercise #1 Indicate if these structures are rigid (R) or non-rigid (NR) R R NR

15. Exercise #2 Add bars to these structures in order to make them rigid

16. STABILITY

17. A structure is stable if it doesn’t topple over easily Two methods are used to give stability: Wider Base Lower Centre of Gravity

18. BASE, wider o narrower? Which structure is the most stable? Why? CONCLUSION: The wider the base area of a structure, the more stable the structure

19. Wider Base

20. Centre of gravity (C.o.G.) If the proyection of C.o.G. is outside the base, the structure topples over

21. If C.o.G. goes up when we tilt the piece, then it’s stable

22. If C.o.G. goes down when we tilt the piece, then it’s unstable

23. Wider Base + Lower C.o.G.

24. DESIGNING STRUCTURES RIGIDITYSTABILITY we must achieve by means of TRIANGULATIONGUSSETS WIDER BASE LOWER C.o.G. by means of

25. THAT’S ALL FOLKS!