| 摘要 |
<p>A structural specimen coated with or constructed of photoelastic material, when illuminated with circularly polarized light will, when stressed, reflect or transmit elliptically polarized light, the direction of the axes of the ellipse and variation of the elliptically polarized light from the illuminating lights corresponds to the direction and magnitude of shear stresses for each illuminated point. Stress analyzing apparatus may or may not use multiple rotating optical elements. A simple polariscope has two polarizing filters with a single one-quarter waveplate placed between the polarizing filters. Light is projected through the first polarizing filter and the one-quarter waveplate and is reflected from a sub-fringe birefringent coating on a loaded structure. Reflected light is analyzed with a polarizing filter. The polarizing filters and the one-quarter waveplate may be rotated together or the analyzer alone may be rotated. Computer analysis of the variation in light intensity yields shear stress magnitude and direction.</p> |
