Influence of the Loading Apparatus on the Stresses within Biaxial Specimens

摘要

The design and construction of a biaxial loading machine is presented in this paper. Two major concerns are ad- dressed in designing the machine: alignment between the loading axes and the specimen, and shear stresses (friction) that may de- velop between the loading platens and the specimen. The alignment requirement is solved by constructing a multi-frame machine in which the horizontal frame hangs from the top of a 890 kN (200 Kip) Baldwin machine by cables and springs, thus allowing dis- placements and rotations of the horizontal loading axis with respect to the vertical axis. Shear stresses between the platens and the spec- imen are reduced by using brush platens.