Chapter 1- Loads And Other Forces

Front 1

AXIAL STRESS

Back 1

Axial stress is produced by an axial force, which can be defined as a force that is parallel to the axis of the member and passes through the centroid of the cross seciton of the member.

Hint 1

A vertical column with a load imposed in compression directly on top of its vertical axis is an example of axial stress.

Front 2

BRITTLE

Back 2

The term pertains to the ability of metals to retain shape under loads

Hint 2

Materials that exhibit little or no yielding before failure. These materials handle compression better than tension. (Cast iron, concrete)

Front 3

BUTTRESSES

Back 3

Projecting structures built against a wall or building to provide greater strength and stability

Hint 3

Horizontal projections of masonry on the exterior of a structure extending from the ground vertically at specific points

Front 4

COMPRESSION

Back 4

Squeezing together; making smaller by direct pressure

Hint 4

Concrete and trusses are good for compression but very poor for tension

Front 5

DEAD LOADS

Back 5

Permanent, inert loads whose pressure on a building is steady and constant due to the weight of its structural members and the fixed loads they carry; these impose definite loads and strains

Hint 5

A dead load is the building itself with all its structural components and the permanently affixed ancillary items, inculding HVAC units, fire escapes, plumbing and electrical equipment, walls, doors, and windows.

Front 6

DUCTILE

Back 6

Capable of being hammered into thin layers or drawn out into wires; the ability of metals to be subjected to stress withouth breaking

Hint 6

A sample that can be subjected to large strains before it ruptures is called a ductile material. The material will stretch before it ruptures.

Front 7

ELASTIC

Back 7

The ability of concrete, metal, or wood members to return to size and shape after deformation under load

Hint 7

If a sample returns to its original size and shape after being stressed under load it is elastic

Front 8

IMPACT LOAD

Back 8

A load delivered unexpectedly to a specific point.

Hint 8

Can be delivered horizontal called lateral impact, or vertically.

Front 9

LIVE LOADS

Back 9

The moving load or variable weight to which a building is subjected, due to the combined weight of the people who occupy it, the furnishings, and other moveable objects.

Hint 9

Live loads include furniture, people, movable equipment, snow and rain

Front 10

PILASTERS

Back 10

Rectangular columns attached to a wall or pier for stiffening. Structurally it's a pier but it is treated as a column with a capital, shaft and base.

Hint 10

Interior application of buttressess.

Front 11

POINT LOADING

Back 11

Imposing a load on a small area relative to its mass.

Hint 11

When a load is concentrated in a small area it is referred to as point loading. This concentration of load must still be delivered through various components until it safely reaches the earth. Example large drill press or heavy equipment.

Front 12

SHEAR

Back 12

Shear is caused by opposing forces that almost meet headon. This type of loading depends heavily on the connectors

Hint 12

These assemblies are attached perpendicular to their supporting members. The load is resting totally on the connectors and support of the load relies on the connectors ability to remain affixed to the supporting structures. Example floor joist hanger.

Front 13

SNOW LOADS

Back 13

Mathematical calculations of the force imposed upon a roof by deposited snow. The wetness and depth of snow are correlated relative to the pitch of the roof.

Hint 13

Snow loads are factored into the design and size of roof structural members based on the antivipated worst possible scenario or the anticipated live load.

Front 14

SPREADER FOOTINGS

Back 14

A footing whose sides slope gradually outward from the foundation to the base.

Hint 14

Foundations are often placed on spreader footings which allow a contiguous sharing of the load and movement, while connectors keep the unit moving as one.

Front 15

TENSION

Back 15

A pulling or stretching force, opposite of compression.

Hint 15

Pulling on a rope/chain is tension force.

Front 16

TORSION

Back 16

The result of twisting

Hint 16

During high winds the force of the wind causes overpressurization and vacuum effects simultaneously on the structure. This twising action will first affect connections.

Front 17

FLEXURAL STRESS

Back 17

Flexural stresses are incurred when the applied force is perpendicular to the axis of the member.

Hint 17

Bending stresses. weight in center of a joist causes compression inwards at the point of the load which bends the joist into concave shape. Tension will point outward from the center of the applied force on the opposide of the joist.

Front 18

DEFORMATION

Back 18

Deformation accompanies stress. Deformation can be defined as the change in the size and shape of a member under load

Hint 18

heavy load bending nail/bolt.

Front 19

TENSILE STRESS

Back 19

Tension stress

Front 20

ECCENTRIC STRESS

Back 20

When a force is applied parallel to the axis of a member but does not pass through the center of the cross section of that member, the stress is eccentric.

Hint 20

A point loading where the weight of the load is resting on a specific point of a floor area adjacent to a column is said to be eccentric to that column.