Term: simple shear
https://doi.org/10.1351/goldbook.S05676

Definition:
An idealized treatment of a fluid between two large parallel plates (to permit ignoring edge effects) of area A, separated by a distance h. If one plate moves relative to the other with a constant velocity V, requiring a force F acting in the direction of movement, and the density, pressure, and viscosity throughout the fluid are constant, the Newtonian equation can be coupled with the equations of motion and of continuity to show that the velocity gradient in the fluid is constant (= V h), and that F/A = η.V/h. This idealized case (simple shear) is sometimes used to define shear viscosity.

Related Terms:
1) viscosity (http://doi.org/10.1351/goldbook.V06627).
2) gradient (http://doi.org/10.1351/goldbook.G02669).
3) shear viscosity (http://doi.org/10.1351/goldbook.S05642).

Source: PAC, 1979, 51, 1213. 'Terminology and Symbols in Colloid and Surface Chemistry Part 1.13. Definitions, Terminology and Symbols for Rheological Properties' on page 1216 (https://doi.org/10.1351/pac197951051213)

Citation: 'simple shear' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.S05676

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