Integrated photoelasticity in a soft material: phase retardation, azimuthal angle, and stress-optic coefficient

Integrated photoelasticity is investigated for a soft material subjected to three-dimensional stress state. In the experiment, solid sphere pressed against gelatin gel (Young's modulus about 4.2 kPa) that deforms up 4.5 mm depending on loading forces. The resulting photoelastic parameters (phase retardation, azimuthal angle, and stress-optic coefficient) in are measured using polarization camera. retardation azimuth compared with analytical prediction based Hertzian contact theory. Remarkably, experimental results of show reasonable agreement not only but also related direction principal stresses rarely validated previous studies, essential reconstructing fields materials. coefficient used 3.12$\times10^{-8}$ 1/Pa. Such findings proved integrated useful measuring field materials, which importance biomedical engineering cell printing applications.