Skip Ribbon Commands
Skip to main content

6H35.50-1 - Stress Kit

The Web Part cannot find an InfoPath form in the specified location. Either the location does not have an InfoPath form associated with it or it is on a different site collection. Modify the Web Part Properties and select a list or library on the current site.

​6H35.50-1 - Stress Kit

Title6H35.50-1 - Stress Kit

Demonstrate how stresses in a material can be seen in polarized light.

Assembly Instructions

​Place unit on overhead projector or on a document camera (if lit from below). Make sure that the screw assembly is out of the viewing area unless requested. Focus the projector (camera). Place serveral different items on an anti-slip mat to protect from scratches and minimize sliding off table.

**Important to remind professors about the lighter and glass**

Setup Time15
Operation Time
Preview Time5
Operation Instructions

Place different samples on to the staging area to view internal stresses.

With the different samples, you can show: stress around cutouts (point, square, round, keyhole), layered mica, safety glasses, screws v. nails, thermal stresses in glass (using lighter). Plastic pieces can be *gently* squeezed to increase stresses.

 Large glass dounut, show stress by cooling down.

There are several polarization examples included in this kit, all of which use the overhead projector in the same manner.One polaroid is located in a rotatable stage located above the main platten where the other non rotatable polarizer is located.All objects placed on the main platten are viewed thru two polarizers and projected on the screen.

Demo on DimeNo
PIRA 200No
Export Instructions (if different)

​On the bottom of the apparatus is a fixed linear polarizer. On the top of the apparatus is a rotatable linear polarizer. These can be adjusted so that varying amounts of light get through. The samples used are optically active materials. They rotate the polarized light and the amount of rotation depends on the color of light and the thickness of the material. This rotation of the polarized light means that not all of the light entering the sample will exit through the second polarizer, and allows us to see a representation of the internal stresses of the samples.

Category6 Optics
Subcategory6H - Polarization
KeywordsGerman mica layer pictures, stress analysis, double refraction in synthetics, polarization, polaroid
Construction Information
The German mica pictures may or may not be mica, it may be cellulose.
stress kit - base with stationary polarizer sheet and rotatable polarizer mounted on elevated assembly
overhead projector
stress kit accessories - glass with lighter, glasses, petri dish, mica sheets, plastic stress cutouts, etc.