ENG 1033 Materials I Lecture 1 Vocabulary

Vocabulary terms and definitions based on the introductory lecture for Materials I, covering historical material ages, failure case studies, and basic loading mechanics.

Bronze

An alloy composed of copper ($Cu$) and tin ($Sn$).

Stone Age

An early period in human history identified with the use of materials like those found in Skara Brae, Orkney, around $3000\,BC$.

Bronze Age

A historical period starting around $3300\,BC$ characterized by the use of copper and tin alloys.

Iron Age

A historical period starting around $1200\,BC$ characterized by the use of iron, such as that found at the Antonine Wall in $143\,AD$.

James Watt Nanofabrication Centre

A facility at the University of Glasgow focused on nanotechnology and the development of future materials.

Tay Bridge Disaster

A railway bridge collapse in $1879$ caused by gale-force winds and a lack of design knowledge regarding side wind pressure.

Tacoma Narrows Bridge

A bridge that collapsed in $1940$ due to excessive vibration and torsion in high winds, where maximum torsion reached $8.5\,m$ between sidewalks.

Liberty Ships

Vessels built between $1941$ and $1945$ using welding and no riveting that suffered fatigue fractures at sharp deck corners, especially in cold temperatures.

Embrittlement

The loss of ductility in the steel of Liberty ships caused by flexing in the sea at low temperatures.

Comet Airliner

The first commercial jet airliner, which suffered catastrophic failures due to crack propagation from sharp window corners during pressurization.

Tension

A loading direction that produces tensile stress in one direction, calculated as $\sigma = \frac{F}{A}$.

Compression

A loading direction that produces compressive stress in one direction, calculated as $\sigma = \frac{F}{A}$.

Torsion

A loading direction that produces shear stresses, calculated as $\tau = \frac{F_s}{A}$ where $A$ is the cross-sectional area.

Hoop Stress

Tensile loads produced in the direction around an object due to a pressure differential, calculated as $\frac{pr}{t}$ where $p$ is pressure, $r$ is radius, and $t$ is wall thickness.

Biaxial Tension

A state of loading that produces tensile stresses in two directions.

Hydrostatic Compression

A state of loading where stress is equal in all directions, such as the pressure on an object underwater due to the weight of water above it.

Units of Stress

The measure of force per unit of cross-sectional area, expressed as $Nm^{-2}$.