College / Engineering


Photoelasticity is used to determine the stress distribution in birefringent plastics, such as polycarbonate. This experiment uses the clear polycarbonate beams from the PASCO Structures System. Two crossed polarizing sheets are placed in front of, and behind, the clear beam. When illuminated from behind by a bright white light, fringes become visible.

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Student Files

20_Photoelasticity.cap 4.22 MB
20_Photoelasticity.pdf 1.07 MB

Featured Equipment

Four-Point Bending Accessory

Four-point Load Anvil

Combine the anvil with the Bending Accessory and perform both three-point and four-point bending on the Materials Testing System.

Photoelasticity Accessory

Photoelasticity Accessory

Set of two crossed polarizing sheets which display stress lines as beams as submit to three-point bending tests.

Bending Accessory

Perform three-point bending tests of various metals.

Materials Testing Machine

Materials Testing Machine

This is the assembly-only version; measures force and displacement for various materials as the materials are stretched, compressed, sheared, or bent.

Many lab activities can be conducted with our Wireless, PASPORT, or even ScienceWorkshop sensors and equipment. For assistance with substituting compatible instruments, contact PASCO Technical Support. We're here to help.

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Source: Lab #20

Comprehensive Materials Testing System