A constant-stress,vacuum creep-testing apparatus

A mathematical analysis is presented for a direct-linkage tensile and compression creep-testing mechanism. A particular design, employing a dead weight, a cam and a linkage system, achieves constant stress in a tensile specimen during uniform creep deformation. Superiority has been achieved over previous designs in: (1) compactness with mechanical advantages up to 10:1, (2) higher structural rigidity and (3) higher sensitivity in the region of small displacements. The advantage of compactness has now made possible the successful design of a vacuum system for high-temperature creep testing at constant stress. Typical creep curves on iron specimens are induced.