Gough–Joule effect


The Gough–Joule effect is originally the tendency of elastomers to contract when heated if they are under tension. Elastomers that are not under tension do not see this effect. The term is also used more generally to refer to the dependence of the temperature of any solid on the mechanical deformation. This effect can be observed in nylon strings of classical guitars, whereby the string contracts as a result of heating.
If an elastic band is first stretched and then subjected to heating, it will shrink rather than expand. This effect was first observed by John Gough in 1802, and was investigated further by James Joule in the 1850s, when it then became known as the Gough–Joule effect.
Examples in Literature:
The effect is important in O-ring seal design, where the seals can be mounted in a peripherally compressed state in hot applications to prolong life.
The effect is also relevant to rotary seals which can bind if the seal shrinks due to overheating.