Application of the least-squares method to elastic and photoelastic calibration of orthotropic composites

New experimental methods continue to be proposed for determining the in-plane elastic constants of orthotropic composite materials, as no single method has been found completely satisfactory. In particular, the in-plane shear modulus is difficult to measure. In this paper, an orthotropic half-plane subjected to a concentrated edge load is proposed as a calibration specimen. Photoelastic calibration of orthotropic-birefringent composites is also difficult due to the need to conserve the commercially unavailable, difficult-to-make model materials and the absence of many closed-form solutions. In this paper, the orthotropic half-plane specimen is proposed for photoelastic calibration of birefringent-orthotropic model materials also. For elastic and photoelastic calibration of orthotropic materials, the least-squares procedure is used for processing the experimental data.