2915 A Multi-Axial Materials Testing System Using 6-DOF Parallel Kinematics
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This paper reports a novel system of multi-axial materials testing system. The proposed system consists of a testing machine, a measuring instrument and a controller. The testing machine is driven by a parallel kinematics (PKM) structure. Making use of the PKM serves not only to achieve complete motions along six axis but also to obtain high dynamical performance. The geometrical relationships of the PKM are derived. We show that the positions of moving platform can be represented as the length of the six limbs of the PKM. The hybrid position/force control scheme derived from a velocity based force control algorithm is introduced, so that we can use velocity-controlled DC servo motors for the PKM. Based on this control scheme, we also propose a method to multi-axial materials testing. The system can be applied to testing on advanced composite materials and components that are difficult to evaluate using conventional testing machines.
