Statics

Applied Forces – All external forces that act on a structure or member
Center of Gravity – A point of balance where the tendency of forces to rotate one side of an object are countered by equal and opposite forces located on the other side of the object
Center of Mass – In an object or system of objects in motion, the center of mass is one point that moves in the same path that a particle would if subjected to the same net force
Centroid – The center of gravity for a two-dimensional shape
Collinear Forces – Forces that act along the same line of action
Component of a Force - Two or more forces that compose a single force
Composite Shapes – Refers to a combination of 2 or more built up shapes
Concurrent Forces - Forces that pass through the same point or intersect at a common point
Coplanar Forces - Forces that act along lines that lie in the same plane
Couple – The effect produced from two forces that have the same magnitude, parallel line of action and opposite sense
Elastic Deformation - Temporary deformation of a material where the material subjected to a load or force returns to its original dimensions once the load or force is removed
External Force - The applied forces that cause an object to translate, rotate or stay at rest
Elastic Range – Range on the stress/strain curve in which a material will return to its original state once the stress is removed
Fixed Support - A fixed support resists translation and rotation of a member at the connection point The reactions of a fixed support compose three unknown forces, including both a vertical and a horizontal component and a resisting moment.
Force - The action of one object exerted on another
Free Body Diagram - A simplified and conceptual diagram that isolates a structural member under investigation from the rest of the structure
Internal Force – Forces that are developed within an object in response to the external loads
Modulus of Elasticity - The ratio of the stress inflicted on an element to the strain that is produced
Moment - The tendency to make an object or a point rotate
Moment Arm - The perpendicular distance between the line of the action of the force and the point
Moment of Inertia – A mathematical concept that incorporates the effect of cross sectional shape and orientation to study the strength of a structural member
Non-Collinear Forces – Two or more forces that act along different lines of action
Non-Concurrent Forces - Forces that do not pass the same point or do not intersect. Parallel forces are an example of non-concurrent forces.
Non-Coplanar Forces - Forces that do not lie in the same plane and have a have a three dimensional arrangement
Parallel Axis Theorem – A mathematical method by which the moment of inertia of a shape with respect to its centroidal axis can be transferred to a prescribed parallel axis that is normally the centroidal axis of the composite shape
Pinned/Hinged Support – A pin or a hinge support resists translation of a member in both horizontal and vertical directions. The reactions of a pin support represent two unknown force components
Plastic Deformation - Deformation that remains permanent in a material subjected to load or force and remains in place even after the load or force is removed
Plastic Range – Range on the stress/strain curve where a material permanently deforms once stress is removed
Radius of Gyration – Defined as the square root of the moment of inertia divided by the cross sectional area of the shape; a shape factor that measures the resistance to bending about a defined axis
Reaction Forces - Equal and opposing forces that resist applies forces
Resultant of a Force – A single force that replaces a system of concurrent forces
Roller Support – A roller support resists translation of a member in the perpendicular direction to the contact surface. This reaction of a roller connection represents one unknown force component.
Static Equilibrium – The state when the net effect of all the forces acting on an object equal zero
Statics – One of three branches of mechanics that deals with the study of forces that are in a state of balance
Stiffness – Measure of a material’s rigidity; a material’s ability to withstand deformations under stress; slope of the stress/strain curve
Strain – Deformation of the physical dimensions of an object subjected to a stress
Stress – Describes the intensity of a force and is expressed by the amount of force acting per unit of area
Transmissibility of Forces – Law that states that the point of application of an external force acting on a body can be moved anywhere along the line of action of the force without creating a change in the overall external forces applied on the body
Ultimate Strength – The maximum force that can be applied to a material without breaking the material
Yield Stress – The point at which stress causes a material to permanently deform