IMP TERMS USED IN CIVIL ENGINEERING

Vocabulary Term	Definition
Body-Centered Cubic	The crystal structure that contains an atom in the center and one atom in each corner of a cube.  Metals with a body-centered cubic crystal structure tend to be hard.
Bond	An attraction that forms when electrons are shared or transferred among atoms.  Atomic bonds become the "glue" that holds the atoms together.
Brinell Test	A hardness test that measures the diameter of a circle formed by the penEetration of a 10mm  steel ball under a fixed load pressure.
Charpy Test	An impact test that measures the amount of energy a material can absorb. The material is broken  by a falling pendulum, and the following upswing of the pendulum is measured.
Cold Working	The shaping of metal at temperatures much lower than the metal's molten state. Steel is  often cold worked at room temperature.
Compression Strength	A material's ability to resist forces that attempt to compress or squeeze the material together.
Compression Stress	A force that attempts to flatten or "squeeze" a material.
Crystal Structure	The formation of crystals, which consist of a repeating pattern of atoms. A crystalline structure  develops as a liquid metal cools and changes into a solid.
Cutting Tool	A device with sharp edges used to cut metal. Cutting tools are either single point or multi-point.
Drawn	The attempt to pull a metal through a die in order to stretch it.
Ductile	Able to be drawn, stretched, or formed without breaking.
Ductility	A metal's ability to be drawn, stretched, or formed without breaking.
Elastic Region	The region of the stress-strain graph in which deformation is temporary. If a material is  forced beyond the elastic region, it experiences plastic deformation.
Face-Centered Cubic	The crystal structure that contains one atom in the center of the six sides of a cube and one  atom in each corner of the cube. Metals with a face-centered cubic crystal structure tend to  be ductile.
Grain	An individual crystal in a metal or alloy.
Hardness	A material's ability to resist penetration, indentation, or scratching. Hard materials tend to be  very wear resistant.
Hexagonal Close-Packed	The crystal structure that contains a collection of atoms that are closely packed into the  shape of a hexagon. Metals with a hexagonal close-packed crystal structure tend to be brittle.
Impact Toughness	The amount of energy that a material can absorb from a sudden, sharp blow before it breaks  or fractures.
Indenter	A device used in a hardness test that is pressed into the test material.
Load	The weight or burden that is supported by a material.
Mechanical Properties	The properties that describe a material's ability to compress, stretch, bend, scratch, dent, or break.
Modulus Of Elasticity	A variable that describes the relationship of stress to strain within the elastic region.  The modulus of elasticity describes a material's stiffness.
Necking	The reduction in diameter that occurs as a sample material is subjected to tensile stresses.
Plastic Deformation	Deformation that is permanent. Plastic deformation occurs after excessive elastic deformation.
Plastic Region	An area of the stress-strain graph in which permanent changes to a metal begin to occur.
Properties	The characteristics of a material that distinguish it from other materials.
Rockwell Test	A hardness test that measures the degree of penetration into a metal caused by a diamond  or other hard material that is applied under a fixed load.
Safety Factor	A number that describes the safe, allowable working stress of a material.
Shear Strength	A material's ability to resist forces that attempt to cause the internal structure of the material to  slide against itself.
Shear Stress	A force that attempts to cause the internal structure of a material to slide against itself.
Slip Band	The appearance of fragmented crystals and spaces indicating that a metal is about to break.
Stamping Die	An assembled device with an upper and lower plate that opens and closes and contains  special tools for cutting or shaping sheet metal.
Steel	A metal consisting of iron and carbon, usually with small amounts of manganese, phosphorus,  sulfur, and silicon.
Strain	The ratio of change in a dimension that takes place with a material under stress.
Strength	A metal's ability to resist outside forces that are trying to break or deform the metal.
Stress	A force that attempts to deform an object.
Stress-Strain Graph	A graph that describes the relationship between stress and strain and marks the elastic  and plastic regions for a given material.
Tensile Strength	A material's ability to resist forces that attempt to pull it apart or stretch it.
Tensile Stress	A force that attempts to pull apart or stretch a material.
Torsion Stress	A type of shear stress that attempts to twist a material against itself.
Toughness	The amount of energy a material can absorb before it breaks.
Yield Strength	The point on the stress-strain curve where there is a sudden increase in strain,  but no increase in stress. It is at this point that a metal is about to permanently deform