1. Structures

2. “The difference between CONSTRUCTION and STRUCTURE: ‘ construction ’ carries a connotation of something put together consciously…”

3. “… while ‘ structure ’ refers to an ordered arrangement of constituent parts…” Eduard Seklar, Structure, Construction, Tectonics

4. Structure is the logic which gives rise to form. It is the set of relations which organize and influence the organization of material Construction is the act or process of putting together or assembling thoughtfully (each are inseparable and in continuous interaction)

5. Deterministic qualities (such as those used in mechanics) provide support for specific decisions operates in a ‘top-down’ way, influencing how we act and what we make

6. Engineering is a convergent process Each decision made gets one closer to an appropriate solution At each step the possibilities are limited. Engineering is an application of a specific and detailed knowledge

7. Engineers use this ‘specific knowledge’ to determine the correctness or appropriateness of an application based on efficiency and economy.

8. MECHANICS : Equilibrium / Stability

10. Static Equilibrium A balanced condition in which a structure (or machine) remains at rest under the action of a specific set of forces.

11. Stability A balanced condition in which a structure remains at rest under the action of all forces.

12. Degrees of Freedom: 3 o of Translation (to move in a straight line) 3 o of Rotation 3-D Space (6 D.O.F.) (X-direction) (Y-direction) (about the Y- direction) 1 2 4 (Z-direction) 3 (about the Z- direction) (about the X- direction) 56 FREE-BODY MOVEMENT

13. For most structural analysis assumptions and approximate methods are often used to simplify analysis into 2-D Space: 2 o of Translation 1 o of Rotation 2-D Space (3 D.O.F.) (X-direction) (Y-direction) (about the Z-direction) 1 2 3

14. Each Degree of Freedom (D.O.F.) of a Free Body must be Restrained. Restraint - a supporting element or boundary condition with the capacity to generate a reaction.

15. Translation caused by a force Force - a measure of an action along a line. To stabilize or maintain static equilibrium the translational D.O.F. must be restrained. Restraint generates a reaction which counters and balances the action. FORCE REACTION FORCE TRANSLATIONAL EQUILIBRIUM

16. R F F Point A To stabilize or maintain static equilibrium the rotational D.O.F. must also be restrained. ROTATIONAL EQUILIBRIUM

22. INSTABILITY OF THE FRAME

27. MECHANICS : Strength / Stiffness/Elasticity

31. Ductility

37. stiffness of buildings Structures also have an overall stiffness based on: –Materials of construction –Joints and connections –Height and geometry

38. stiffness of buildings

39. tuned mass damping Taipei 101 Building in Taiwan. Completed 2003-2004. Overall height 509 m (1671 ft). 728-ton counterweight ball hung at 87 th /88 th floor Behavior of this damper during the 2008 Szechuan earthquake and Aug 2015 Typhoon Soudelor

40. Deformation or Deflection Minute changes in shape induced by the forces acting on a structure