Virtual Work Principle For A Rigid Body
If the principle of virtual work for applied forces is used on individual particles of a rigid body, the principle can be generalized for a rigid body: When a rigid body that is in equilibrium is subject to virtual compatible displacements, the total virtual work of all external forces is zero; and conversely, if the total virtual work of all external forces acting on a rigid body is zero then the body is in equilibrium.
The expression compatible displacements means that the particles remain in contact and displace together so that the work done by pairs of action/reaction inter-particle forces cancel out. Various forms of this principle have been credited to Johann (Jean) Bernoulli (1667-1748) and Daniel Bernoulli (1700-1782).
Read more about this topic: Virtual Work
Famous quotes containing the words virtual, work, principle, rigid and/or body:
“Tragedy dramatizes human life as potentiality and fulfillment. Its virtual future, or Destiny, is therefore quite different from that created in comedy. Comic Destiny is Fortune—what the world will bring, and the man will take or miss, encounter or escape; tragic Destiny is what the man brings, and the world will demand of him. That is his Fate.”
—Susanne K. Langer (1895–1985)
“There is a hearty Puritanism in the view of human nature which pervades the instrument of 1787. It is the work of men who believed in original sin, and were resolved to leave open for transgressors no door which they could possibly shut.”
—James Bryce (1838–1922)
“I do not mean to exclude altogether the idea of patriotism. I know it exists, and I know it has done much in the present contest. But I will venture to assert, that a great and lasting war can never be supported on this principle alone. It must be aided by a prospect of interest, or some reward.”
—George Washington (1732–1799)
“They work, and age, and put off men
By being unattractive, or too shy,
Or having morals anyhow, none give in:
Some of them go quite rigid with disgust
At anything but marriage....”
—Philip Larkin (1922–1986)
“... what a family is without a steward, a ship without a pilot, a flock without a shepherd, a body without a head, the same, I think, is a kingdom without the health and safety of a good monarch.”
—Elizabeth I (1533–1603)