A
ABET:Accrediting Board for Engineering and Technology.
Abrading: The process of removing material by applying friction
Abutment: The part of a structure (as an arch or a bridge) that directly receives thrust or pressure.
Acceleration: Exists when the velocity of a particle changes with time.
Acceptance level: The maximum number of defects in a sample that will permit acceptance of the entire lot.
Accumulator: A device (as in a hydraulic system) in which a fluid is collected and especially in which it is kept under pressure as a means of storing energy.
Accuracy: Degree of conformity of a measure to a standard value.
Acoustical: Of or relating to the sense or organs of hearing, to sound, or to the science of sounds.
Actuator: A device that transfers fluid or electrical energy into mechanical energy.
Adhesion: The process of fastening two parts by the application of a third material such as glue, epoxy, etc.
Allowable Stress: Level of stress judged to be permissible in a design.
Alloy: A substance composed of two or more metals or of a metal and a nonmetal intimately united usually by being fused together and dissolving in each other when molten.
Alternator: An electric generator for producing alternating current
Analog: Of, relating to, or being a mechanism in which data is represented by continuously variable physical quantities.
Angle: The union of two co-planar rays intersecting at a common endpoint.
Annealing: The process of softening metal for improved machinability or cold working by heating it to its critical temperature, holding it there until the temperature is uniform, then cooling it slowly at a controlled rate.
Arch Bridge: a bridge that uses long span arches for support”
Assembly:Consisting of individual parts fitted together to create a final product
ASTM:American Society for Testing and Materials
Attribute Listing: idea generation listing and combining the attributes associated with a situation.
Austenite: a solid solution in iron of carbon and sometimes other solutes that occurs as a constituent of steel under certain conditions
Automation: A machine or system that operates with minimal human control: using automated machines as control for production.
Axial Force: Force aligned along the central axis of a material.
B
Bar Chart: A graph in which the data is represented by horizontal or vertical bars.
Beam Bridge: A bridge whose main structural element consists of a beam set across two or more vertical supporting members.
Bearings: Devices used to reduce friction between rotating shafts and fixed carriers. Examples are roller, ball, and air bearings
Belt: A continuous band that transmits motion from one pulley to another.
Benchmark: A point of reference for making measurements or judgments.
Bernoulli’s Law: A change in the velocity of a fluid caused by a constriction produces an opposite change in pressure.
Blow Molding: Method of fabrication in which a warm plastic parison (hollow tube) is placed between the two halves of a mold cavity and forced to assume the shape of that mold cavity by use of air pressure.
Bonding: Adhering materials with cement or glue.
Boyle’s Law: The volume of a gas at a constant temperature is inversely proportional to its pressure.
Brainstorming: A group problem-solving technique that involves the spontaneous contribution of ideas from all members of the group; during this process, ideas are shared but not critiqued.
Brazing:Sometimes called hard soldering. Joining pieces of metal togetherbelow the point of fusion by melting a third.
British Thermal Unit (BTU): The US Customary unit of thermal energy; the amount of energy needed to raise the temperature of one pound of pure water by one degree Fahrenheit.
Brittleness: The description for a material, which is neither ductile nor malleable and will fail suddenly without warning.
Broaching: a precision machining process used to change the shape of a hole into another shape (e.g. a square or keyhole); a broach is used to do this.
Bronze Age:The period of ancient human culture characterized by the use of bronze that began between 4000 and 3000 B.C. and ended with the advent of the Iron Age.
Buckling:Failure caused by bending, giving way, or crumpling due to excessive force.
C
CAD: computer-aided design; drafting or solid modeling performed on a computer.
Cadmium Sulfide Cell: A light sensitive resistor; also known as a photocell
CAM: computer-aided manufacturing; aiding in the manufacturing process through the use of computer technology
Cp: Capability Index, a measure of how capable a machine or process is to stay within the limits given for that process or machine
Cable-stayed Bridge: A bridge in which the deck is supported on either side of a central tower or towers by cables. Unlike a suspension bridge, the cables that hold the deck attach directly to the tower, rather than hanging from a larger cable running between the towers.
Calendaring: The process of forming plastic sheets by squeezing a thermoplastic material between a series of rollers.
Caliper: any of various measuring instruments having two usually adjustable arms, legs, or jaws used especially to measure diameter or thickness -- usually used in plural <a pair of calipers> (0) see example of dial caliper below:
Calorie: A metric unit of thermal energy; the amount of energy needed to raise the temperature of one gram of pure water by one degree Celsius; A Calorie (capital C) is a “food calorie” and is 1000 calories); 1.00 calorie = 4.186 Joule.
Cam: A mechanical device used to change simple rotary motion into a more complex motion.
Cam Cycle: one complete 360º rotation of a cam.
Carbide: A compound of carbon with one or more metallic elements.
Carbon: A nonmetallic chiefly tetravalent element found native (as in the diamond and graphite) or as a constituent of coal, petroleum, and asphalt, of limestone and other carbonates , and of organic compounds or obtained artificially in varying degrees of purity especially as carbon black, lampblack, activated carbon, charcoal, and coke (Webster.com)
Carburizing: (Cementation) Adding carbon to the surface of iron-base alloys by absorption through heating the metal at a temperature below its melting point in contact with carbonaceous solids, liquids or gasses. The oldest method of case hardening.
Case Hardening: Carburizing and subsequently hardening by suitable heat-treatment all or part of the surface portions of a piece of iron-base alloy.
Case study: A broad-based analysis of an engineering problem.
Casting: The process of producing an object by pouring a heated liquid material into a mold and allowing it to solidify by cooling.
Catapult: A system used to launch objects. (Ancient catapults used bent wood as the power source, modern systems use power such as steam.)
Cell:A single space for an entry in a spread sheet
Center of Gravity: The point at which the entire weight of a body may be considered as concentrated so that if supported at this point the body would remain in equilibrium in any position. Same location as center of mass.
Center of Mass: The point in a body or system of bodies at which the whole mass may be considered as concentrated. Same location as center of gravity.
Centi: a prefix meaning one hundredth or 1/100 or 10-2; symbol: c
Centroid: A point whose coordinates are the averages of the corresponding coordinates of a given set of points and which for a given plane or three-dimensional figure (as a triangle or sphere) corresponds to the center of mass of a thin plate of uniform thickness and consistency or a body of uniform consistency having the same boundary.
Cementite: A compound of iron and carbon known as “Iron Carbide,” which has the approximate chemical formula Fe3C containing 6.69% of carbon. Hard and brittle, it is the hard constituents of cast iron, and the normal form in which carbon is present in steel. It is magnetizable, but not as readily as ferrite.
Center Line: A line consisting of a long dash followed by a short dash, that is used to show and locate centers of arcs and circles, and to describe the center axis of cylindrical forms.
Ceramic: A compound of metallic and nonmetallic elements, for which the interatomic bonding is predominantly ionic.
Chain: A continuous band consisting of metal or plastic links that transmits motion from one sprocket to another.
Charles’ Law: The volume of a gas at a constant pressure is directly proportional to its temperature.
Chart:A sheet or map giving information in the form of a table, list or diagram
Chemical: Of, relating to, used in, or produced by chemistry.
Chemical energy: The energy associated with chemical bonds and bonding structure. This includes the energy associated with changes in phase from solid to liquid to gas. Chemical energy does not lend itself to an equation. Rather, there are tabulated values associated with all known elements and compounds, as well as values for the most common chemical reactions.
Chronological:Arranged in or according to the order of time.
Circle: A closed curve with coplanar points at the same distance from the center point.
Class of Fit:Fits are arranged in three general groups known as running and sliding fits, locational fits, and force fits
Closed loop: The output of a process is constantly monitored and the input adjusted according to feedback provided by sensors.
Cohesion: The process of fusing two like materials for the purpose of fastening. Examples include friction welding, spot welding, electron beam welding and laser welding).
Cold forming: The process of working metal into shape below the temperature of recrystallization. Cold forming improves the strength; machinability, dimensional stability and surface finish of metals.
Communication: The act of transmitting useful data or ideas to one or more receivers; can be one-way or two-way.
Component: A single device or part in an assembly
Component Relational Sketch:A pictogram showing the relationship of how the components react together in a system.
Composite: A multiphase material formed from a combination of materials that differ in composition or form, remain bonded together, and retain their identities and properties.
Compound: A substance of two or more elements in fixed proportions. Compounds can be decomposed into their constituent elements.
Compression: The effect of a force, which tends to shorten an object in the direction of the force. Such a force is called a compressive force, and the object it acts on is said to be in compression. For example, the towers of a suspension bridge are in compression.
Compression molding: A forming process in which a powdered thermosetting plastic is placed in a heated mold cavity then compressed by a ram. After being compressed, the plastic solidifies, the ram retracts, and the part is ejected.
Compressor: A device that converts mechanical force into pneumatic energy.
Computer aided drafting (CAD): The use of a computer to create drawings.
Computer Numeric Control (CNC): A combination of a computer, a digital control system and a machine tool that enables the machine to accept standard codes and automatically make parts.
Concurrent: Occurring at the same time; running parallel; acting in conjunction.
Conditioning: The process of treating a material to achieve physical, electrical, or mechanical properties.
Conduction: (Thermal definition) The transfer of heat energy by physical contact.
Conflict Of Interest: Moral dilemma from dual responsibilities or loyalties.
Contour: An outline, especially of something curved or irregular.
Constraints: Restrictions or guidelines.
Contribution: To supply a significant part.
Control Limits: (Lower and upper control limits (LCL and UCL)); these describe what the process is actually giving you; they are random variables that are a function of the process itself; they are observed or calculated, not set.
Convection: The transfer of heat energy by moving a heated substance from one place to another.
Conveyer: A belt like device used to move objects.
Coplanar: Occurring in the same plane.
Counter bore: A larger drilled hole concentric with a smaller diameter hole. The larger hole is not as deep as the smaller hole.
Countersink: A beveled or conical surface at the top of a drilled hole for the purpose of accepting a bolt head.
Coupling: A system used to connect and transfer energy from one part to another - usually shafts that rotate.
Crankshaft: A shaft that has journals, which changes reciprocating motion to rotary motion.
Creep:The slow change of dimensions of an object from prolonged exposure to high temperature or stress.
Critical Component: A component in a system that, if it fails, renders the entire system useless. In reliability studies, Critical Components are the focus of improvement efforts.
Critical temperature (points): Temperatures at which internal changes or transformations take place within a metal either on a rising or falling temperature.
Crystalline: In some resins a state of molecular structure denoted by uniformity and compactness of the molecular chains. This characteristic is attributable to the existence of solid crystals with definite geometric form.
Current: The total amount of electrons flowing through a circuit per unit time; measured in Amperes (one coulomb of electrons passing a single point per second).
D
Data: Information (measurements or statistics) used as a basis for reasoning, discussion, calculation or transmission.
Data base: 1) Collection of similar information in a computer file; a database can be divided into records and fields; 2) A facility which is a central point for the collection and dissemination of various types of information.
Deflection:A measure of deformation of a structure due to applied loads
Deformation: Change in size and/or shape of a body due to stress. (0).
Delphi Technique: Individuals contribute solution ideas independently to a central office.
Delta: Greek letter used in mathematical formulae to represent change.
Density: Mass per unit volume.
Design: Translation of a concept into a satisfactory, producible, salable form.
Design brief: A format for stating a design problem.
Design Constraints: Requirements and limitations under which the design process takes place.
Desktop Publishing: Creating and publishing a document using a PC and output device such as a laser printer.
Destructive Testing: Material or product testing in which information is learned about the material/product via careful measurements and recordings as the material/product is destroyed.
Detail: Shape or feature on a model.
Deviation: The difference between the actual measurements of a product and the design specifications.
Diagonal: A line that is slanting or oblique
Dial Indicator:A precision measurement device accurate to at least one thousandths of an inch used to measure inside and outside dimensions and depths of materials with the output being read using a dial.
Diaphragm: Part of a pump that consists of a flexible membrane.
Digital: An information system whose signals have only two states, 1 (closed) or 0 (open).
Dilemma: A choice between equally unpleasant courses of action.
Dimension Line: Thin line segment capped on the ends with arrowheads, that indicate the length of the dimension.
Dimension: Numerical value used on a drawing to describe location, size, shape, or geometric characteristic.
Dimensioning: The process of placing measurements and notes on a drawing to completely communicate its meaning.
Dimensional:A measure in one direction; specifically: one of three coordinates determining a position in space or four coordinates determining a position in space and time.
Discipline: An area of study
Displacement Diagram:(Re: cams) A drawing that represents the desired motion of the cam. The length of the diagram is equal to the circumference of the working circle. The height of the diagram is equal to the radius of the working circle. The length of the diagram is divided into intervals representing degrees of rotation of the cam, a common interval would be 30 degrees. The smaller the interval, the more accurate the cam profile:
Displacement: Movement of an object through a distance.
Drilling: To bore or drive a hole in. A machining process that produces a hole.
Ductility: Property of materials that will undergo plastic deformation or elongation of more than 5% before fracture.
Dwell: That segment of cam rotation that causes the follower to remain stationary
Dynamics: The behavior of matter when in motion; (physics) the study of why objects move.
E
Eccentric: A device that rotates in an off-center position on an axle or shaft.
Edge: The line where two surfaces or points intersect.
Elastomers: Any of various elastic substances; An amorphous, cross-linked high polymer that will stretch rapidly under tension, reaching high elongations (500 to 1000%).
Electron Discharge Machining (EDM): A separating process that produces a spark between an electrode and the work piece causing an erosion action. This process can only be used on electrically conductive materials.
Elastic Modulus (Young’s Modulus or the Modulus of Elasticity): The ratio of stress to strain when deformation is totally elastic; also a measure of the stiffness of a material.
Elastic Potential Energy: The energy that can be stored in the compression or extension of an elastic material (traditional springs included). The equation for the energy stored in a spring is SE= ½ kx2 where “k” is the spring constant (or modulus of elasticity for a solid ) and “x” is the distance of extension or compression.
Electromagnet: A core of magnetic material surrounded by a coil of wire through which an electric current is passed to magnetize the core.
Electromagnetic energy: The energy associated with electricity, magnetism, and electromagnetic waves.
Elastomer:A polymeric material that may experience large and reversible elastic deformations.
Electrical:Of, relating to, or operated by electricity.
Electrode: A conducting element that emits or collects electrons or ions or controls their movement
Electronic: The use of electronics to control a system or machine.
Element: A substance that cannot be decomposed into simpler substances by chemical means.
Ellipse: The group or set of all points in the same plane whose sum of distances from two points (foci) is constant. An ellipse looks like a squashed circle or a circle viewed at an angle.
Engineering: A course of study followed by a professional career that involves complex analysis, design and development of solutions to technical problems.
Engineering technology: A course of study followed by a professional career that involves testing, troubleshooting, servicing and maintenance of technical product sand systems.
English system: (U.S. Customary System) A measurement system in which the fundamental units are the foot, slug, and second.
Environment:The ecological community that one lives in
Equilibrium: A state of balance due to the equal action of opposing forces in a structure. (0).
Essence: The quality or nature of something that identifies it or makes it what it is.