The transfer-grid method,a practical Moiré stress-analysis tool

A practical and simple moiré stress-analysis technique is described. The grid is applied to any part by a transfer method, like a decal, not necessitating mechanical engraving or photoetching nor any special environmental care. The moiré fringes are observed remotely from the part without master contact. This is done through the use of a projection device and a master held in a plane where the projected image of the working grid is formed. Limitations of the method, as well as its applications, are discussed.