Salginatobel Bridge Robert Maillart a threehinged arch TYPES

Salginatobel Bridge Robert Maillart, a three-hinged arch

TYPES OF JOINTS • Metals Pin Connection Rigid Connection

TYPES OF JOINTS • Reinforced Concrete Pin Connection Rigid Connection

Connection models Better connection model

CEE 3404: Review of Statics

Reactions Civil Engineering: Structures are designed to be in Static Equilibrium (Satisfy Newton’s First Law) a) Structure is at REST. b) Structure does NOT tend to TRANSLATE: c) Structure does NOT tend to ROTATE:

Reactions (Contd. ) • Three-dimensional case: å Mz = 0 ; å My = 0 å Mx = 0

Reactions (Contd. ) • Two-dimensional case:

Reactions (Contd. ) Civil Engineers use: • Support connections to attach structures to the ground (Reaction forces and moments) • Connections to attach the members that compose the structure Equilibrium of the structure is maintained

Methodology - Reaction forces and moments computation Step # 1: Identify “object” of interest (entire structure or a piece of the structure). Step # 2: Draw Free Body Diagram (FBD) showing all external forces. Step # 3: Resolve forces into components and set:

Methodology – Reaction forces and moments computation Step # 4: Pick an appropriate point and set: Step # 5: Solve these equations for the unknown reactions forces and/or moments. Step # 6: (If necessary) repeat Step # 1 – # 5 for a different “object. ”

External and Internal Forces • EXTERNAL FORCES: actions of other bodies on the structure under consideration. Examples: applied forces (loads) and reactions • INTERNAL FORCES: are the forces and couples exerted on a member or portion of the structure by the rest of the structure.

Example Actual Beam Idealized Beam

Example Pinned. S upport Rocker support Hinged Support

Example Idealized Beam Line Drawing

Idealized supports – 2 -D structures

Idealized supports – 2 -D structures