This paper describes a data reduction methodology for eliminating the systematic aberrations introduced by the unwanted behavior of a multiaxial testing machine, into the massive amounts of experimental data collected from testing of composite material coupons. The machine in reference is a custom made 6-DoF system called NRL66.3 and developed at the NAval Research Laboratory, that consists of multiple sets of hexapod configurations essentially forming a recursive synthesis of multiple parallel mechanisms. Hexapod linkages, the grips, and other deformable parts of the machine absorb energy. This is manifested in an either reversible or irreversible manner, thus introducing a parasitic behavior that is undesirable from the perspective of our ultimate goal of the material constitutive characterization. The data reduction focuses both on the kinematic (pose of the grip) and the reaction (forces and moments) that are critical input quantities of the material characterization process. The kinematic response is reduced by exploitation of the kinematics of the dots used for full field measurements. A correction transformation is identified by solving an inverse problem that minimizes the known displacements at the grips as given by the full field measurements and those given by the machine’s displacement sensors. A Procrustes problem formalism was introduced to exploit a known material behavior tested by the testing machine. Consequently, a correction transformation was established and was applied on the load cell data of the machine in order to eliminate the spurious responses appearing in the force and moment data.

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