When the tendons have stretched sufficiently, according to the design specifications ( see Hooke's law ), they are wedged in position and maintain tension after the jacks are removed, transferring pressure to the concrete.

Hooke's law in simple terms says that stress is directly proportional to strain.

In terms of Young's modulus and Poisson's ratio, Hooke's law for isotropic materials can then be expressed as

Because Hooke's law neglects higher order terms ( so only the linear term dominates ), in certain cases, such as rubbery materials, these conditions may not hold.

When Robert Hooke discovered Hooke's law in 1660, he first published it in anagram form, ceiiinosssttuv, for ut tensio, sic vis ( Latin: as the tension, so the force ).

Reversible elastic deformation in metals can be described by Hooke's Law for restoring forces, where the stress is linearly proportional to the strain.

The classical theory of elasticity deals with the behaviour of elastic solids under small deformations, for which ,( 1 ) according to Hooke's Law, stress is directly proportional to the strain — but independent of the rate of strain, or how fast the deformation was applied, and ( 2 ) the strains are completely recoverable once the stress is removed.

These behaviour are, of course, generally observed for ideal materials under ideal conditions, although the behaviour of many solids approaches Hooke's law for infinitesimal strains, and that of many fluids approaches Newton's law for infinitesimal rates of strain.

* Hooke's law, for the mathematical model of certain processes

Based on this fact, many writers in the past and even the present have given Huygens the credit for inventing the modern form of spiral balance spring in 1675 rather than Hooke's earlier straight spring of 1665 because they considered that the spiral form automatically conferred the property of isochronism on the oscillating balance.

Hooke developed an air pump for Boyle's experiments based on the pump of Ralph Greatorex, which was considered, in Hooke's words, " too gross to perform any great matter.

Instruments were devised to measure a second of arc in the movement of the sun or other stars, to measure the strength of gunpowder, and in particular an engine to cut teeth for watches, much finer than could be managed by hand, an invention which was, by Hooke's death, in constant use.

None of this should distract from Hooke's inventiveness, his remarkable experimental facility, and his capacity for hard work.

" Hooke's work on elasticity culminated, for practical purposes, in his development of the balance spring or hairspring, which for the first time enabled a portable timepiece – a watch – to keep time with reasonable accuracy.

A bitter dispute between Hooke and Christiaan Huygens on the priority of this invention was to continue for centuries after the death of both ; but a note dated 23 June 1670 in the Hooke Folio ( see External links below ), describing a demonstration of a balance-controlled watch before the Royal Society, has been held to favour Hooke's claim.

Hooke's 1666 Royal society lecture " On gravity " added two further principles – that all bodies move in straight lines till deflected by some force and that the attractive force is stronger for closer bodies.

In Hooke's time, the Royal Society met at Gresham College, but within a few months of Hooke's death Newton became the Society's president and plans were laid for a new meeting place.

Wren's challenge to Halley and Hooke, for the reward of a book worth thirty shillings, was to provide, within the context of Hooke's hypothesis, a mathematical theory linking the Kepler's laws with a specific force law.

Hooke's law models the properties of Spring ( device ) | springs for small changes in length

Materials for which Hooke's law is a useful approximation are known as linear-elastic or " Hookean " materials.

Hooke's law only holds for some materials under certain loading conditions.

Steel exhibits linear-elastic behavior in most engineering applications ; Hooke's law is valid for it throughout its elastic range ( i. e., for stresses below the yield strength ).

For some other materials, such as aluminium, Hooke's law is only valid for a portion of the elastic range.

Newton, faced in May 1686 with Hooke's claim on the inverse square law, denied that Hooke was to be credited as author of the idea, giving reasons including the citation of prior work by others before Hooke.

Newton, faced in May 1686 with Hooke's claim on the inverse square law, denied that Hooke was to be credited as author of the idea, giving reasons including the citation of prior work by others before Hooke.

Robert Hooke's Micrographia had a huge impact, largely because of its impressive illustrations.

* When the system is displaced from its equilibrium position, a restoring force which resembles Hooke's law tends to restore the system to equilibrium.

The book and its inscription in Hooke's hand are a testament to the lasting influence of Wilkins and his circle on the young Hooke.

A lesser-known contribution however one of the first of its kind was Hooke's scientific model of human memory.

In 1676 British physicist Robert Hooke discovered the principle behind springs ' action, that the force it exerts is proportional to its extension, now called Hooke's law.

As long as they are not stretched or compressed beyond their elastic limit, most springs obey Hooke's law, which states that the force with which the spring pushes back is linearly proportional to the distance from its equilibrium length:

Hooke's law of elasticity states that the extension of an elastic rod ( its distended length minus its relaxed length ) is linearly proportional to its tension, the force used to stretch it.

Hooke's law is a mathematical consequence of the fact that the potential energy of the rod is a minimum when it has its relaxed length.

According to Hooke's law the magnitude of the force exerted by a spring is linearly proportional to its extension.

The tension ( elastic force ) in a spring is proportional to its extension according to Hooke's law.

For an anisotropic solid such as wood or paper, these three moduli do not contain enough information to describe its behaviour, and one must use the full generalized Hooke's law.

As another quick example, Hooke's Law () describes the force produced by a spring when stretched a distance < var > x </ var > from its resting position, and is another example of a direct proportion: k in this case has units N / m ( in metric ).

Objects that quickly regain their original shape after being deformed by a force, with the molecules or atoms of their material returning to the initial state of stable equilibrium, often obey Hooke's law.

Hooke's experiments led him to conclude that combustion involves a substance that is mixed with air, a statement with which modern scientists would agree, but that was not widely understood, if at all, in the seventeenth century.

Moreover, Montagu found that contemporary written descriptions of Hooke's appearance agreed with one another, but that neither matched Times alleged picture of him.

Hooke's gravitation was also not yet universal, though it approached universality more closely than previous hypotheses.

Hooke's gravitation was also not yet universal, though it approached universality more closely than previous hypotheses.