Structures Midterm

Types of stresses

Compression, tension, bending (shear, torsion)

Loads

Live, dead, lateral, snow

Live load

Loads that are not permanent and can move/be removed

Dead load

Permanent loads

Lateral load

Horizontal loads, mainly winds

Load paths

Route forces take to get to the ground

Stiffness

Defined by orientation

Cantilever needs…

Rigid supports and a back span or weight

Buckling

Failure of a column after succumbing to compression

Structural system

Stable assembly of elements that safely transfer forces to the ground without the system failing

Brittle material

Snappy and can fail suddenly

Ductile material

Squishy and bendy

Deflection

Deformation like sagging

Transverse load

Perpendicular

Axial load

Same direction that element is going

Roller support

Resists only vertical forces

Pinned support

Resists only vertical and horizontal forces

Fixed connection

Resists horizontal, vertical, and rotational forces

Stability

Ability to resist gross deformation

What does depth do

Thickens element and allows for longer span

What is “span”?

Distance between supports

What is “length“

Length of a structure

What are the 2 types of a cable stay bridge?

Fan and harp

Fan cable stay bridge

Cables from one point at top of tower

Harp cable stay bridge

Cables positioned vertically down the tower

Funicular

Ideal form for specific load case

Applied load

Load that is not self weight

Self weight

Weight of structure

Strut

Compression diagonal

Tuned mass damper

A heavy weight connected to a building that is used to reduce seismic and wind activity

What makes a corbeled arch “corbeled”?

It is stepped

Taxonomy

Study of general principles of scientific classification: systematics

Ways to classify structures

form, behavior, materials, spanning ability

Form

shape/geometry

Behavior

How does it transferer loads

Materials

Wood, concrete, steel, masonry (glass, carbon fiber)

Beam classification

Rigid linear

Beam material

Wood, steel, concrete

Beams work in…

Bending

Column classification

rigid linear

Column material

Wood, steel, concrete, masonry

Columns work in…

compression

Columns are loaded…

axially

Frame classification

rigid linear

a frame is…

composed of columns and beams that can be braced

Frame material

wood, steel, concrete

Mt Hope Bridge

steel suspension bridge

Frames work in…

bending and compression

Truss classification

made up of linear rigid

Truss material

wood, steel, concrete

Truss wooks in…

bending with individual members working in tension or compression

Arches classification

curved linear element

Arches work in…

compression

Arches material

wood, steel, concrete, masonry

Walls and Plates classification

Planar surface

Walls and Plates work in…

compression or bending

Cylindrical shells and vaults classification

singe curved surface

Cylindrical vaults on columns work in…

compression and bending

Cylindrical vaults on walls work in…

compression

Cylindrical vaults can’t hold…

point loads

Spherical shells and domes are…

solid or articulated (framed)

membranes, tents and nets classification

single or double curved surface

membranes work in…

tension

ica

cantilever

sea ranch

timber framing and multiple buildings

space frames work in…

tension and compression

space frame materials

wood and steel