SS Flashcards
A push or pull exerted on an object. Includes its magnitude, direction, and point of application.
Force
1 kip
1000 pounds
A force applied to a body
Load
An internal force in a body that resists an external force
Stress
A line parallel to an in line with a force
Line of Action
Describing the condition when the lines of action of several forces pass through a common point
Concurrent
One force that will produce the same effect as two or more other forces
Resultant
A force equal in magnitude to the resultant, but opposite in direction and on the same line of action as the resultant
Equilibrant
Replacing a force with two or more other forces (components) that will produce the same effect on a body as the original force
Resolving Forces
The TENDENCY of a force to cause rotation about a given point or axis
Moment (M)
Two forces equal in magnitude, but opposite in direction, and acting at some distance from each other
Couple
A state of rest due to balanced forces and balanced moments
Equilibrium
Forces acting at the supports of a structure that hold the structure in equailibrium
Reactions
The point in a cross-section where all of the area may be considered concentrated without affecting the moment of the area about any axis
Centroid
The product of an area and the distance from the centroid of the area to a given axis
Statical Moment
The sum of the products obtained by multiplying each unit of area by the square of its distance to the neutral axis
Moment of Inertia
Stress that tends to stretch a member or pull it appart
Tension
Stress that tends to shorten a member or crush it
Compression
Stress that tends to make two members, or two parts of a member, slide past each other
Shear
The deformation (change in size) of a body caused by external forces
Strain
The physical law that states that up to a certain unit stress, called the elastic limit, unit stress is directly proportional to unit strain
Hooke’s Law
The unit stress for a material, below which Hooke’s Law applies
Elastic Limit
Within the elastic limit, the constant ratio of the unit stress in a material to the corresponding unit strain
Modulus of Elasticity
Resistance to deformation
Stiffness
The unit stress at which a material deforms with no increase in load
Yield Point
The maximum unit stress that can be developed in a material
Ultimate Strength
The maximum unit stress permissible in a structural member
Working Stress or Allowable Stress
The ratio of the ultimate strength of a material to its working stress
Factor of Safety
The ratio of unit strain to temperature change, which is constant for a given material
Coefficient of Thermal Expansion
A beam that rests on a support at each end and whose ends are free to rotate
Simple Beam
A beam that is restrained against rotation at one end and free at the other
Cantilever Beam
A beam that rests on two or more supports and has one or both ends projecting beyond the support
Overhanging Beam
One of two or more forces that will produce the same effect on a body as a given force
Component
A beam that rests on more than two supports
Continuous Beam
A beam that is restrained (fixed) against rotation at both ends
Fixed End Beam