Photoelastic Demonstration (FL 210)

generate stress patterns with linear or circular polarised light in typical polycarbonate components



  • Photoelasticity can be used to demonstrate stress profiles and stress concentrations in component models.
  • The distribution of stress in plane, transparent bodies (plastic models) is investigated using polarised light.
  • Polarising filters represent the stress profiles in colour.
  • The notching and point loading and the criteria dictating component design are clearly visualised.
  • The FL 210unit can be used with overhead projectors.
  • Various transparent plastic models are mounted inside a frame.
  • A load application device is used to apply pressure or tensile loads to the model under investigation through a spindle.
  • An arrangement of polarising filters and quarter-wave filters generates either linear or circular polarised light.
  • A green filter to generate monochromatic light is also part of the scope of delivery.
  • The light source is an overhead projector (e.g., FL 210.01).
  • The use of monochromatic light produces a system of dark and light stripes, which reflect the distribution and magnitude of mechanical stresses.
  • The models which belong to the scope of delivery represent typical components, permitting experimentation in relation to notching and point loading.
  • The stress profiles shown on the model are identical to those in real-world components.
  • Additional models are also available to represent stress profiles in roller bearings, tooth flanks, screw connections and wrenches.
  • All parts of the experiment are clearly laid out and securely housed in a storage system.

Technical Details:


  • photoelastic experiments with an overhead polariscope
  • polariser and analyser each comprise a polarising filter and a quarter-wave filter
  • filter enclosed, with stress-free glazing
  • all filters arbitrarily rotatable in the horizontal plane
  • linear or circular polarised light possible
  • green filter for monochromatic light
  • load application device with force gauge for pressure and tensile load
  • eight different polycarbonate models are delivered
  • storage system for parts

Technical Data:

  • Filter bracket with polariser and analyser:
    • diameter of filters: Ø 165mm
  • 1 green filter, diameter: Ø 150mm
  • Load application device with force gauge:
    • load force: 0…250N
  • 8 models, PC:
    • unnotched bar
    • bar with hole
    • bar notched on one side
    • bar notched on both sides
    • rectangle without recesses
    • rectangle with recesses
    • fork
    • crane hook

Dimensions & Weight:

  • L x W x H: 500x190x30mm (frame)
  • L x W x H: 280x280x90mm (filter bracket)
  • Weight: approx. 8kg
  • L x W x H: 1170x480x178mm (storage system)

Learning Objections/Experiments:

  • generate plane stress states in various models under load
    • compressive load
    • tensile load
  • investigate stress distributions with linear and circular polarised light
  • interpret photoelastic fringe patterns
    • stress distribution
    • stress concentration

Scope of Delivery:

  • 1 frame with load application device
  • 1 filter bracket with polariser and analyser
  • 1 green filter
  • 8 photoelastic models
  • 1 storage system with foam inlay
  • 1 set of instructional material


  • demonstration unit as an attachment for an overhead projector
  • generate stress patterns with linear or circular polarised light in typical polycarbonate components
  • detect stress concentrations


Due to the continuous development of our products, the goods supplied may vary in detail to that illustrated on this Website.