STRESS MEASURING METHOD, STRESS MEASURING MEMBER, AND STRESS MEASURING SET

摘要

The present invention provides a stress measuring method including: irradiating a photoelastic product including a measurement subject with light penetrating a linear polarizing film and a phase difference film in this order, and detecting reflected light from the product which is derived from the light via the phase difference film and the linear polarizing film in this order, in which in-plane retardation Re (550) of the phase difference film with light having a wavelength of 550 nm satisfies 100 nm≦Re (550 nm)≦700 nm, and in-plane retardation Re (450) of the phase difference film with light having a wavelength of 450 nm satisfies Re (450)/Re (550)≧0.9, a stress measuring member including the linear polarizing film and the phase difference film, and a stress measuring set including the stress measuring member and a stress displaying member including a photoelastic layer.