Circumferential shear test method and apparatus for a sandwich structure

A test fixture for determining circumferential shear properties of an arcuate test specimen may include an outer fixture and an inner fixture. The outer fixture may be coupled to an outer side of the test specimen, and may be rotatably mounted on a central pin and may include a rocker arm. The inner fixture may be coupled to an inner side of the test specimen, and may be rotatably mounted on the central pin and may include a load arm extending in a direction opposite the rocker arm. The inner fixture and the outer fixture may be configured such that application of a test load to the rocker arm and the load arm causes rotation thereof about the central pin producing circumferential movement of the inner side relative to the outer side and inducing a circumferential shear load in the test specimen.