A Study of Dynamic Holographic Photoelasticity Using Ruby Laser

A solution to the problem of principal stress distribution on the boundary of a circular hole and on a section of the model in semi-infinite plate during passage of the stress wave is presented. The solution was obtained experimentally by using a polyester material model, utilizing a double-pulsed Ruby Laser with energy/pulse of 0.25 joule. The stress pulse was applied by loading with reproducible falling weight of the pendulum. Utilizing an external event to initiate the firing order of Ruby Laser and using a different time delay, we have recorded, respectively, the isochromatic and isopachic fringes at one model using a Faraday Rotator.

Holographic photoelasticity: Influences of inaccuracies of optical retarders on isochromatics and isopachics

In this paper the influence of inaccuracies of the optical retarders on the isochromatic and isopachic fringes obtained by holographic photoelasticity is studied. For the single-exposure hologram it is shown that the isochromatic visibility decreases as for light- and dark-field configurations, whereas the isochromatic fringes are distorted only for the dark-field configuration. For the double-exposure hologram it is shown that the isopachic fringes are generally distorted; with the isochromatics there is a decrease of fringe visibility. Experimental results confirming the theory are reported.