A Biaxial Tension-Torsion, Constant Stress, Creep Testing Machine

Abstract

Biaxial tension-torsion hydraulic machines are available commercially together with a few specific devices directly constructed by the users (Tapsell and Johnson, 1940; Trampczynski, Morrison and Topliss, 1980; Henderson and Dyson, 1982).In the case of high temperature properties creep plays a predominant part and occurs with low strain rates ($\dot \varepsilon {10^{ - 6}}{s^{ - 1}}$) for which hydraulic systems are not well adapted, particularly for long duration tests. The device described here is aimed at performing low strain rate tests and allowing a large range of load paths; proportional or non-proportional loading under constant or variable stresses. The machine allows high temperature (${900^ \circ }C$) tests at constant stress.