An introduction to dynamic photoelasticity

The general area of elastodynamics is divided into four more limited topics including, stress-wave propagation, vibration and impact, fracture propagation and quasi-static transients. The application of dynamic photoelasticity to each topic is discussed. Recording methods used in dynamic photoelasticity which are reviewed include the high-speed framing camera, the Cranz-Schardin system, Q-switched ruby lasers, and a stopaction strobe system. Advantages and disadvantages of each method of recording are covered. Analysis procedures used in interpreting the dynamic isochromatic-fringe patterns are described. Examples are illustrated where separation of the principal stresses is possible and a calibration method for determining the dynamic material-fringe valuef σ * is reviewed. Finally, four applications of dynamic photoelasticity to problems arising in geophysics, fracture mechanics, flaw detection and mining are briefly reviewed to show the versatility of the dynamic photoelastic method are described.