An image†shearing Moiré method to record partial slopes of flexed plates

A new Moiré method is proposed to map partial slope contours of laterally loaded reflective plate models. The beam of light reflected by the plate is collected by a field lens and is optically sheared by a thin glass plate at the focus to produce slope modulated gratings at the image plane. No real grating is used. Sensitivities an order higher than those of classical Moiré methods are obtained. © 1984 Blackwell Publishing Ltd