Development of a tri-axial load cell based on strain gages

A tri-axial load cell of cantilever type for the measurements of an axial f orce (F-z) and two bending forces (F-x, F-y) was developed to study fractur e toughness under mixed-mode loading condition. The full scale of load cell is +/-1.5kN axial force, +/-1.5kN bending forces, respectively. The load c ell consists of three Wheatstone full bridge arrangements to increase the h igh sensitivity and compensate the ambient temperature. To decouple three f orces components, active eight strain gages for the axial force and four ga ges for bending force are used in the bridge circuit. The calibration of lo ad cell showed that the coupling effects of each force were almost negligib le, and the load cell was found to have linear characteristics without any hysteresis. The accuracy was +/-0.6% of full scale (+/-1.5kN).