Measurement of contact stresses using real-time shearing interferometry

The optical method coherent gradient sensing, a real-time lateral shearing interferometry, is proposed for measuring contact stress fields under stati c and dynamic loading conditions. Feasibility of the method is first establ ished under quasi-static conditions. Under dynamic conditions, the method h as been used in conjunction with high-speed photography. The interference p atterns representing stress gradients are used for extracting impact load h istory. Loading rates of approximately 14 MN/sec have been observed. The op tical measurements are compared with the computed values obtained using fin ite element simulations. (C) 1999 Society of Photo-Optical Instrumentation Engineers. [S00913286(99)01811-5].