Measurement of contact stresses using real-time shearing interferometry

The optical method coherent gradient sensing, a real-time lat- eral shearing interferometry, is proposed for measuring contact stress fields under static and dynamic loading conditions. Feasibility of the method is first established under quasi-static conditions. Under dynamic conditions, the method has been used in conjunction with high-speed photography. The interference patterns representing stress gradients are used for extracting impact load history. Loading rates of approximately 14 MN/sec have been observed. The optical measurements are com- pared with the computed values obtained using finite element simula- tions. © 1999 Society of Photo-Optical Instrumentation Engineers. (S0091-3286(99)01811-5)