Unit 2
Cable
A strong rope, usually made of metal, designed to have great tensile strength and to be used in structures.
Centroid
The geometric center of an area.
Compression Force
A body subjected to a push.
Concurrent Force Systems
A force system where all of the forces are applied at a common point on the body or having their lines of action with a common intersection point.
Cross-Sectional Area
A surface or shape exposed by making a straight cut through something at right angles to the axis.
Direction
The direction of a vector is defined by the angle between a reference axis and the arrow’s line of direction.
Fixed Support
A support that prevents translation and rotation in a beam.
Flange
A broad ridge or pair of ridges projecting at a right angle from the edge of a structural shape in order to strengthen or stiffen it.
Free Body Diagram
A diagram used to isolate a body from its environment, showing all external forces acting upon it.
Gusset
A plate or bracket for strengthening an angle in framework.
Joint
The connection points of members of a truss.
Magnitude
The absolute value of a number.
Member
Slender straight pieces of a truss connected by joints.
Method of Joints
A method of analysis of trusses which constructs free body diagrams of each joint and determines the forces acting in that joint by considering equilibrium of the joint pin.
Moment
The turning effect of a force about a point equal to the magnitude of the force times the perpendicular distance from the point to the line of action from the force.
Moment of Inertia
A mathematical property of a cross section that is concerned with a surface area and how that area is distributed about a centroidal axis.
Newton’s First Law
Every body or particle continues at a state of rest or uniform motion in a straight line, unless it is compelled to change that state by forces acting upon it.
Newton’s Second Law
The change of motion of the body is proportional to the net force imposed on the body and is in the direction of the net force.
Newton’s Third Law
If one body exerts a force on a second body, then the second body exerts a force on the first body which is equal in magnitude, opposite in direction, and collinear.
Pinned Support
A support that prevents translation in any direction.
Planar Truss
A truss that lies in a single plane often used to support roofs and bridges.
Resultant Force
The resultant of a system of force is the vector sum of all forces.
Roller Support
A support that only prevents a beam from translating in one direction.
Scalar
A physical quantity that has magnitude only.
Sense
The sense of a vector is the direction of the vector relative to its path and indicated by the location of the arrow.
Simple Truss
A truss composed of triangles, which will retain its shape even when removed from supports.
Static Equilibrium
A condition where there are no net external forces acting upon a particle or rigid body and the body remains at rest or continues at a constant velocity.
Statically Indeterminate
A structure or body which is over-constrained such that there are more unknown supports than there are equations of static equilibrium.
Structure
Something made up of interdependent parts in a definite pattern of organization, such as trusses, frames, or machines.
Tension Force
A body subjected to a pull.
Vector Quantity
A quantity that has both a magnitude and direction
A strong rope, usually made of metal, designed to have great tensile strength and to be used in structures.
Centroid
The geometric center of an area.
Compression Force
A body subjected to a push.
Concurrent Force Systems
A force system where all of the forces are applied at a common point on the body or having their lines of action with a common intersection point.
Cross-Sectional Area
A surface or shape exposed by making a straight cut through something at right angles to the axis.
Direction
The direction of a vector is defined by the angle between a reference axis and the arrow’s line of direction.
Fixed Support
A support that prevents translation and rotation in a beam.
Flange
A broad ridge or pair of ridges projecting at a right angle from the edge of a structural shape in order to strengthen or stiffen it.
Free Body Diagram
A diagram used to isolate a body from its environment, showing all external forces acting upon it.
Gusset
A plate or bracket for strengthening an angle in framework.
Joint
The connection points of members of a truss.
Magnitude
The absolute value of a number.
Member
Slender straight pieces of a truss connected by joints.
Method of Joints
A method of analysis of trusses which constructs free body diagrams of each joint and determines the forces acting in that joint by considering equilibrium of the joint pin.
Moment
The turning effect of a force about a point equal to the magnitude of the force times the perpendicular distance from the point to the line of action from the force.
Moment of Inertia
A mathematical property of a cross section that is concerned with a surface area and how that area is distributed about a centroidal axis.
Newton’s First Law
Every body or particle continues at a state of rest or uniform motion in a straight line, unless it is compelled to change that state by forces acting upon it.
Newton’s Second Law
The change of motion of the body is proportional to the net force imposed on the body and is in the direction of the net force.
Newton’s Third Law
If one body exerts a force on a second body, then the second body exerts a force on the first body which is equal in magnitude, opposite in direction, and collinear.
Pinned Support
A support that prevents translation in any direction.
Planar Truss
A truss that lies in a single plane often used to support roofs and bridges.
Resultant Force
The resultant of a system of force is the vector sum of all forces.
Roller Support
A support that only prevents a beam from translating in one direction.
Scalar
A physical quantity that has magnitude only.
Sense
The sense of a vector is the direction of the vector relative to its path and indicated by the location of the arrow.
Simple Truss
A truss composed of triangles, which will retain its shape even when removed from supports.
Static Equilibrium
A condition where there are no net external forces acting upon a particle or rigid body and the body remains at rest or continues at a constant velocity.
Statically Indeterminate
A structure or body which is over-constrained such that there are more unknown supports than there are equations of static equilibrium.
Structure
Something made up of interdependent parts in a definite pattern of organization, such as trusses, frames, or machines.
Tension Force
A body subjected to a pull.
Vector Quantity
A quantity that has both a magnitude and direction
2.2 Material Properties
Additive Process
The process of creating an object by adding small pieces or layers together to make a final product.
Ceramic
Of or relating to the manufacture of any product (as earthenware, porcelain, or brick) made essentially from a nonmetallic mineral (as clay) by firing at a high temperature.
Codes
A systemized body of laws; a set of principles, as of ethics.
Composite
Solid material which is composed of two or more substances having different physical characteristics and in which each substance retains its identity while contributing desirable properties to the whole; especially, a structural material made of plastic within which a fibrous material (as silicon carbide) is embedded.
Decision Matrix
A tool for systematically ranking alternatives according to a set of criteria.
Finishing
Machining a surface to size with a fine feed produced in a lathe, milling machine, or grinder.
Forming
A process that changes the size and shape of a material by a combination of force and a shaped form.
Liability
Anything for which a person is legally bound or responsible.
Manufacturing
To make into a product suitable for use; to make from raw materials by hand or by machinery; to produce according to an organized plan and with division of labor.
Material
The elements, constituents, or substances of which something is composed or can be made; matter that has qualities which give it individuality and by which it may be categorized.
Mechanical Properties
Those properties of a material that reveal the elastic and inelastic reaction when force is applied, or that involve the relationship between stress and strain; for example, the modulus of elasticity, tensile strength, and fatigue limit.
Metals
Any of various opaque, fusible, ductile, and typically lustrous substances that are good conductors of electricity and heat.
Physical Properties
Properties other than mechanical properties that pertain to the physics of a material and can usually be measured without the application of force.
Polymers
Any of numerous natural and synthetic compounds of usually high molecular weight consisting of up to millions of repeated linked units, each a relatively light and simple molecule.
Product Life Cycle
Stages a product goes through from concept and use to eventual withdrawal from the marketplace.
Raw Material
Crude or processed material that can be converted by manufacture, processing, or combination into a new and useful product; something with a potential for improvement, development, or elaboration.
Recycling
Returning to an original condition. The extraction and recovery of valuable materials from scrap or other discarded materials.
Subtractive
Processes that remove material to change the size, shape, or surface of a part. There are two groups of separating processes: machining and shearing.
Synthetic
Produced by the combining of parts or elements to form a whole, rather than of natural origin; not real, artificial.
The process of creating an object by adding small pieces or layers together to make a final product.
Ceramic
Of or relating to the manufacture of any product (as earthenware, porcelain, or brick) made essentially from a nonmetallic mineral (as clay) by firing at a high temperature.
Codes
A systemized body of laws; a set of principles, as of ethics.
Composite
Solid material which is composed of two or more substances having different physical characteristics and in which each substance retains its identity while contributing desirable properties to the whole; especially, a structural material made of plastic within which a fibrous material (as silicon carbide) is embedded.
Decision Matrix
A tool for systematically ranking alternatives according to a set of criteria.
Finishing
Machining a surface to size with a fine feed produced in a lathe, milling machine, or grinder.
Forming
A process that changes the size and shape of a material by a combination of force and a shaped form.
Liability
Anything for which a person is legally bound or responsible.
Manufacturing
To make into a product suitable for use; to make from raw materials by hand or by machinery; to produce according to an organized plan and with division of labor.
Material
The elements, constituents, or substances of which something is composed or can be made; matter that has qualities which give it individuality and by which it may be categorized.
Mechanical Properties
Those properties of a material that reveal the elastic and inelastic reaction when force is applied, or that involve the relationship between stress and strain; for example, the modulus of elasticity, tensile strength, and fatigue limit.
Metals
Any of various opaque, fusible, ductile, and typically lustrous substances that are good conductors of electricity and heat.
Physical Properties
Properties other than mechanical properties that pertain to the physics of a material and can usually be measured without the application of force.
Polymers
Any of numerous natural and synthetic compounds of usually high molecular weight consisting of up to millions of repeated linked units, each a relatively light and simple molecule.
Product Life Cycle
Stages a product goes through from concept and use to eventual withdrawal from the marketplace.
Raw Material
Crude or processed material that can be converted by manufacture, processing, or combination into a new and useful product; something with a potential for improvement, development, or elaboration.
Recycling
Returning to an original condition. The extraction and recovery of valuable materials from scrap or other discarded materials.
Subtractive
Processes that remove material to change the size, shape, or surface of a part. There are two groups of separating processes: machining and shearing.
Synthetic
Produced by the combining of parts or elements to form a whole, rather than of natural origin; not real, artificial.