Forces in Engineering Flashcards
Vector quantity referring to the change in velocity with a change in time (m/s2)
It can be calculated as: final velocity minus initial velocity (measured in m/s) divided by final time minus in- itial time
acceleration
Angular separation between two objects as perceived by an observer (Source: www.thefreedictionary.- com/angular distance)
angular distance
Forces which cause a structural element to bend under strain
bending forces
Amount of stress a material can withstand before breaking
breaking strength
Property of a material, which does not bend under strain and breaks easily when a mechanical shock is ap- plied for example.
illustration ductile vs. brittle: https://www.youtube.com/watch?v=JFSn_XsAvho
brittleness
result of flexion bending forces applied onto an object
buckling
Point through which the result of the weight of all the particles of the body acts
Illustration by TutorVista.com: https://www.youtube.com/watch?v=R8wKV0UQtlo
centre of gravity
Forces which cause a structural element, which withstand the strain, to decrease in size or in volume e.g. decrease in length and cross section
compressive forces
permanent or non permanent change in shape, which is often described in terms of strain, due to an app- lied force (e.g. bending f., compressive (pushing) forces (twisting), tensile (pulling) forces, or shear forces, torsion
deformation
measure of the amount of matter contained by a given volume
density
mechanical property of metal to stretch under certain conditions of heat, pressure and tensile forces in or- der to be drawn into wire.
illustration ductile vs. brittle: https://www.youtube.com/watch?v=JFSn_XsAvho
ductility
Non permanent changing in shape (e.g. stretch or increase in length) due to a tensile force
elastic deformation
Property by virtue of which a material deformed under the load but can regain its original dimensions when unloaded
elasticity
Forces, which cause buckling
flexion bending forces
influence that may cause a body to accelerate or change in shape. It may be experienced as a lift, a push, or a pull, and has a magnitude and a direction. The actual acceleration of the body is determined by the vec- tor sum of all forces acting on it
bending forces: Forces which cause a structural element to bend under strain
tensile forces: Forces which cause a structural element to stretch i.e. to increase in length while often to de- crease in cross section
compressive forces: Forces which cause a structural element which withstand the strain, to decrease in size or in volume e.g. decrease in length and cross section
flexion bending forces: Forces, which cause buckling
shear forces: Forces, which push in opposite direction at different points of the body
torsion forces: Forces which are resulting of applying a moment onto an object fasten to a wall for example.
force
Force that opposes the relative motion or tendency toward such motion of two surfaces in contact. Engineers consider two main kind of friction:
- static friction and
- dynamic friction
friction
property of a material or an object to resist most of the mechanical forces without deforming
hardness
amount of matter contained by a given volume
mass
Force multiplied by the perpendicular distance between the force and the pivot. It is often just ‘moment’, though there are other quantities of that name such as moment of inertia) is a quantity that represents the magnitude of force applied to a rotational system at a distance from the axis of rotation.
N.B.: Moment of a force is similar as ‘torque’
moment (of a force)
Permanent deformation of material due to a force applied onto it
plastic deformation
property of a solid body whereby it undergoes a permanent change in shape or size when subjected to a stress exceeding a particular value (the yield value)
plasticity
movement of an object in a circular motion. A two-dimensional object rotates around a centre (or point) of rotation. A three-dimensional object rotates around a line called axis
rotation
Forces, which push in opposite direction at different points of the body
shear forces
scalar quantity with dimensions distance/time i.e scalar value expressing the rate of motion, or equivalent- ly the rate of change of position, many times expressed as distance d travelled per unit of time t.
speed
a description of deformation in terms of relative displacement. Ratio of change in dimension relati- ve to the original dimension
3 types of strain :
- linear strain (ratio of change in length to the original length)
- volume or bulk strain (ratio of change in volume to the original volume)
- shearing strain is equal to the angle of shear
strain
internal distribution of force per unit area that balances and reacts to external loads applied to a body
stress
Forces which cause a structural element to stretch i.e. to increase in length while often to decrease in cross section
tensile forces
The maximum amount of tension a material can withstand
tensile strength
it is defined by linear force multiplied by a radius. It is often informally be thought of as “rotational force” or “angular force” which causes a change in rotational motion.
N.B. Similar notion as ‘moment’ or ‘moment of a force’
torque
Forces which are resulting of applying a moment onto an object fasten to a wall for example
torsion forces
the rate of change of the position of an object with respect to a frame of reference, and is a function of time
velocity
Plastic deformation that occurs at a specific amount of stress (0,2% plastic strain)
Yield strength
also called ‘modulus of elasticity’, Stiffness of the material when the material is undergoing deformation
Young’s modulus
