Structures Midterm

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What is “span”?

The distance between supports

What is “length”?

How long a structure actually is

What is “depth”?

How deep the material is

What is span to depth ratio?

The relationship between span and depth, the longer the span the deeper the depth

What is a cantilever

A structure supported at one end only

What does a cantilever need to work?

Rigid supports and a back span or weight

What are the 3 type of connections?

Roller, pin and rigid

What are the parts of a bridge?

Towers, deck and cables

What does the towers of a bridge work in, bending, compression, or tension?

Compression

What does the deck of a bridge work in, bending, compression, or tension?

Bending

What does the cables of a bridge work in, bending, compression or tension?

Tension

What are ways of classifying structures?

Materiality, form, function, load path, spanning

What are the typical materials used?

Concrete, steel, wood, masonry (and sometimes glass)

What is dead load?

Things that stay in place

What is live load?

Movable things

What does it mean when a material is brittle?

A material is snappy and can fail suddenly.

What is a cable stay bridge?

A bridge that uses cable and steel.

What are the 2 types of a cable stay bridge?

Fan and harp

What is a fan cable stay bridge?

The cables radiates like a fan

What is a harp cable stay bridge?

The cables are parallel to each other

What does a cable stay bridge work in, bending, compression or tension?

Tension

What is a suspension bridge?

A bridge that has one main cable with two towers.

What does a suspension bridge work in, bending, compression or tension?

Tension

What is a tuned mass damper?

An object made that is used to stiffen structure to work against wind load.

What makes a true arch “true”?

It has a keystone

What makes a corbeled arch “corbeled”?

It is stepped

What inventions allowed development of high rise buildings?

The invention of the elevator and air conditioning

What is a beam?

A horizontal rigid linear element

What does a beam work in, bending, compression, or tension?

Compression

What is it called when a beam is sagging?

Deflection

What material(s) can be used to make a beam?

Wood, concrete, and steel

What is a column?

A vertical rigid linear element

What does a column work in, bending, compression, or tension?

Compression

What happens when a column fails?

It buckles

What material(s) can be used to make a column?

Wood, concrete, steel, and masonry.

What happens when columns are thin?

They are weaker and can buckle

What kind of column is stronger?

When they are build wider and hollow and could be filled with concrete

What is slender length ratio?

The more the slender, the smaller the length

What is a frame?

A combination of beams and frames.

What does a frame work in, bending, compression, or tension?

Bending

What happens when a frame fails?

It leans

What material(s) can be used to make a frame?

Wood, steel, and reinforced concrete

What can you do to make a frame more rigid?

Bracing, using tension and compression

What are the 3 ways to make frames?

Rigid connections, diagonal bracing, and sheer wall.

What kind of spans can a frame be used on?

Limited spans

What is a truss?

A structural system made of linear rigid elements arranged in triangular patterns

What does a truss work in, bending, compression or tension?

Bending

What does the individual members of a truss work in, bending, compression, or tension?

Compression and tension

What material(s) can be used to make a truss?

Wood and steel

What kind of spans can a truss be used on?

Long spans

What is a truss usually used to build?

Roofs

What is an arch?

A curved linear element

What does an arch work in, bending, compression, or tension?

Compression

What material(s) can be used to make an arch?

Wood, steel, concrete and masonry

What kind of connections do an arch have?

Fixed, two-hinge, three-hinge

What is a wall?

A vertical rigid planar element

What is a plate?

A horizontal rigid planar element

What does a wall work in, bending, compression or tension?

Compression

What does a plate work in, bending, compression or tension?

Bending

What material(s) can be used to make a wall?

Wood, concrete, and masonry

What material(s) can be used to make a plate?

Wood and concrete

What is a cylindrical shell and vault?

A rigid, single curved surface element

What does cylindrical shells and vaults work in, bending, compression or tension?

Bending and compression

How does cylindrical shells and vaults fail?

If it has point load

What material(s) can be used to make cylindrical shells and vaults?

Wood, concrete and masonry

When does a cylindrical shell and vault work in bending?

When supported by columns

When does a cylindrical shell and vault work in compression?

When supported by continuous walls

What is a spherical shell and dome?

A rigid, doubly curved linear and planar element

What does a spherical shell and dome work in, bending, compression, or tension?

Bending and compression

What material(s) can be used to make a spherical shell and vault?

Wood, concrete and masonry

What kind of spans can a spherical shell and dome be used on?

Long spans

What is a spherical shell and dome usually used to build?

Roofs

What is a membrane?

Thin flexible sheet, surface

What is a tent?

Temporary structure composed of membrane surfaces

What is a net?

A tensile grid

What does a membrane, tent and net work in, bending, compression or tension?

Tension

What material(s) can be used to make a membrane, tent and net?

Cables and fabric

What is a membrane, tent and net usually used to builld?

Roofs

What is a space frame?

A “3D truss”

What does a space frame work in, bending, compression or tension?

Bending

What material(s) can be used to make a space frame?

Wood and steel

What kind of spans can a space frame be used on?

Long spans

What is a space frame usually used to build?

Shells, roofs, and walls

What is a geodesic dome?

A structure composed of many repeating linear rigid elements

What does a geodesic dome work in, bending, compression, or tension?

Compression and tension

What material(s) can be used to make a geodesic dome?

Steel, aluminum and wood

What is significant about geodesic domes?

It closes the most volume with the least materials (yet usually useless)

What is a pneumatic structure?

A structure that is air inflated or air supported

What does a pneumatic structure work in, bending, compression, or tension?

Tension

What material(s) can be used to make a pneumatic structure?

Fabric

What is a tensegrity structure?

A structural system that maintains its form through a balance of continuous tension and discontinuous compression that is lightweight

What does a tensegrity structure work in, bending, compression or tension?

Compression and tension

What material(s) can be used to make a tensegrity structure?

Steel

What kind of spans can a tensegrity structure be used on?

Long spans

What is a tensegrity structure usually used to build?

Roofs

What is a spatial/grid structure?

Intersecting rigid lines that is planar or curved that makes a surface

What does a spatial/grid structure work in, bending, compression, or tension?

Compression and tension

What material(s) can be used to make a spatial/grid structure?

Wood and steel

What kind of spans of spans can a spatial/grid structure can be used on?

Long spans

What is a spatial/grid structure usually used to bridge?

Roofs