AN APPARATUS FOR BIAXIAL STRENGTH TESTING OF STANDARD TENSILE SPECIMENS

A novel, low cost testing apparatus has been designed for the application of biaxial stress on standard tensile specimens. The apparatus independently applies compressive loading perpendicular to a tensile load. The compressive load is transferred through a compression pad, applying hydrostatic pressure to the test section. The experimental results of tests conducted on 6061-T6 aluminum have been analyzed and compared using the von Mises failure criterion. The results indicate that using this test apparatus with a polytetrafluoroethylene (PTFE) compression pad produces biaxial failures consistent with the failure envelope defined by the von Mises failure criterion.