The deviations from Hooke's law in whiskers in elastic uniaxial tension experiments are related to higher-order elastic constants. We derive this relation for an arbitrary crystal system and whisker-tension-axis orientation to fourth order in the strain. The deviations from Hooke's law are experimentally found for copper and nickel whiskers. The results are compared with other methods of determining third-order elastic constants.

• Received 8 January 1973

DOI:https://doi.org/10.1103/PhysRevB.8.466