Biaxial and Shear Testing Apparatus With Force Controls

An apparatus for in-plane biaxial tension/compression and in-plane shear testing of fabrics, other flexible sheet materials, or relatively rigid thin plate materials has been invented. The apparatus is capable of applying, to a sheet material specimen, a controlled tensile or compressive force along each of two directions in the plane of the specimen. The force along each direction can differ from the force along the other direction. The directions of the applied forces can be orthogonal or can be set at an oblique angle, depending on the combination of stresses required to be applied to the specimen. Thus, depending on the angle between the applied-force directions, the sense (tensile or compressive) of each applied force, and the magnitude of each force, the specimen can be subjected to almost any combination of in-plane shear and biaxial tension/compression loading.