Measurement of in‐plane elastic moduli of composites with a circular disk specimen and piezoelectric sensors

Many test specimen configurations and test methods have been used for measuring the in-plane elastic constants of orthotropic composites. While the measurement of the Young's modulus is straightforward, the shear modulus determination is more difficult. Most of the experimental methods require more than one specimen for the measurement of all the in-plane elastic constants. In the proposed method, a single test specimen in the form of a circular disk is sufficient. The Young's modulus and the shear modulus are measured with piezoelectric sensors that produce and detect dilatational and shear waves, respectively. The experimental techniques involved and the possible methods of interpreting the results are explained. The results obtained were compared with those determined for bar specimens of the same material, using piezoelectric sensors and strain gauges. The comparisons are encouraging. POLYM. COMPOS., 26:542–551, 2005. © 2005 Society of Plastics Engineers