Internal Stress Measurement

Example Measurements

The figure to the right shows an example of the optical stress that arises when mechanically stressing a U-shaped plastic part as indicated. The direction of the stress is displayed by the colour and the arrows, the strength of the stress being displayed by the colour saturation and the length of the arrows. Concentration of stress at the inside corners which varies with the applied pressure is clearly visible. A feature of the PA-100 is to be able to display the internal stress of an actual sample instantaneously.

Analytical data is displayed in 3D, the amount of stress being represented by the height at each point.
The stress distribution is displayed intuitively making it suitable for presentation to a wide audience.
The upper figure shows the radial distribution of the stress of a CD case in the vicinity of the injection gate.
The lower figure clearly shows the optical phase difference created by a prism sheet.

The image of the stress distribution of a pair of reading glasses clearly shows a concentration of stress around the nose.
The effect of the lens material and dimensional accuracy on the stress distribution can be evaluated by measuring and displaying the direction and amount of stress simultaneously.

The image to the right is of a segmented wave-plate similar to the SWP-1064 fabricated using our photonic crystal technology.
The evaluation of compound optical elements, which were previously difficult to evaluate is also possible.