Establishing multiaxial testing capabilities for tubular and planar specimens

摘要

Because of the desire to improve accuracy of plasticity models under multiaxial stress/strain states, and the need to test orthotropic materials such as composites, Sandia/CA developed two separate digitally-controlled materials testing systems. One is for Axial/Torsional/Pressure testing of tubular specimens instrumented with either strain gages (small strains) or a multiaxial extensometer (large strain). System capacity is 440kN (100,000pounds) axial plus 6kN-m (50,000inch-pounds) torsion plus 200MPa (30,000psi) internal pressure. The other is a planar biaxial system with 2MN (500,000pounds) capacity for testing composites and metals, with provisions for 1MN (250,000 pounds) in a third orthogonal axis for testing of pressure-sensitive materials and geomaterials.