Dynamical Calibration of a Standard Sensor-Based Experimental Test Apparatus for Accurate Material Model Parametric Identification

A signal processing-based procedure is proposed for calibrating an experimental sensor-based test system used to identify material model parameters. A standard dynamic mechanical analyzer (DMA) sensorized test apparatus is considered, enabling the measurement of dynamic excitation and displacement response in a specimen under flexural conditions. To account for the dynamic contributions of the system frame and fixtures to the measured response, a novel calibration procedure is introduced, mainly differing from the techniques used in standard test applications. A multi-degree-of-freedom dynamic model of the instrument frame, coupled with the beam specimen under test, is considered, and a frame identification procedure is described. The proposed procedure requires measurements from at least three beam specimens made of a known material but with different geometries. It is shown that an accurate frame model can be identified using an algebraic numerical technique. It is shown that the accuracy of the material model identification can be improved by applying the proposed calibration technique. Some experimental application examples are presented and discussed.