shear

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Figure 5: (A) Extensional strain and (B) simple shear strain, where the element drawn with dashed lines represents the reference configuration, and the element drawn with solid lines represents the deformed configuration.

shear

mechanics

Also known as: shear strain

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July 13, 2026

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Figure 5: (A) Extensional strain and (B) simple shear strain, where the element drawn with dashed lines represents the reference configuration, and the element drawn with solid lines represents the deformed configuration.

In mechanics, shear refers to a type of stress that tends to cause deformation by slippage along planes within a material. This occurs when forces are applied parallel to a cross-sectional area, causing different sections or layers to move in different directions.12

Shear stress is crucial in understanding natural phenomena like landslides and earthquakes. It can affect solids and liquids, with its behavior in liquids related to viscosity. In solids, shear stress can arise from actions like twisting a metal bar.13

A shear strain is the resulting deformation. It's characterized by a change in the right angles within the material, deforming squares into diamond shapes. The shear modulus quantifies a material's resistance to these transverse deformations, representing the ratio of shear stress to shear strain. This property is vital for designers to prevent structural failure by selecting materials that can withstand anticipated stresses.456

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viscosity
…proportional to the rate of shear strain, or rate of deformation, that results. In other words, the shear stress divided by the rate of shear strain is constant for a given fluid at a fixed temperature. This constant is called the dynamic, or absolute, viscosity and often simply the viscosity.…
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…proportional to the rate of shear strain, or rate of deformation, that results. In other words, the shear stress divided by the rate of shear strain is constant for a given fluid at a fixed temperature. This constant is called the dynamic, or absolute, viscosity and often simply the viscosity.…
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glacier
Glacier flow
…of plastic deformation under constant shear stress is initially high but tapers off to a steady value. If this steady value, the shear-strain rate, is plotted against the stress for many different values of applied stress, a curved graph will result. The curve illustrates what is known as the flow…
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…of plastic deformation under constant shear stress is initially high but tapers off to a steady value. If this steady value, the shear-strain rate, is plotted against the stress for many different values of applied stress, a curved graph will result. The curve illustrates what is known as the flow…
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materials testing
Static shear and bending tests
Inplane shear tests indicate the deformation response of a material to forces applied tangentially. These tests are applied primarily to thin sheet materials, either metals or composites, such as fibreglass reinforced plastic.
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Inplane shear tests indicate the deformation response of a material to forces applied tangentially. These tests are applied primarily to thin sheet materials, either metals or composites, such as fibreglass reinforced plastic.
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shear modulus
The shear modulus is a measure of the ability of a material to resist transverse deformations and is a valid index of elastic behaviour only for small deformations, after which the material is able to return to its original configuration. Large shearing forces lead to flow…
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The shear modulus is a measure of the ability of a material to resist transverse deformations and is a valid index of elastic behaviour only for small deformations, after which the material is able to return to its original configuration. Large shearing forces lead to flow…
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shear wave
…it is subjected to periodic shear. Shear is the change of shape, without change of volume, of a layer of the substance, produced by a pair of equal forces acting in opposite directions along the two faces of the layer. If the medium is elastic, the layer will resume its…
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…it is subjected to periodic shear. Shear is the change of shape, without change of volume, of a layer of the substance, produced by a pair of equal forces acting in opposite directions along the two faces of the layer. If the medium is elastic, the layer will resume its…
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