Photoelastic experiments with a transmission polariscope (FL 200)

Photoelastic experiments with a transmission polariscope (FL 200)

generate stress patterns with linear or circular polarised light

CodeFL200

Description:

  • Photoelasticity is a proven method of analysing and recording mechanical stresses and strains in components.
  • It is used both for quantitative measurements and for demonstrating complex stress states.
  • The components used are models made of a transparent, photoelastically sensitive plastic, which becomes optically birefringent under mechanical load.
  • FL 200is used to conduct photoelastic experiments on plane, transparent plastic models.
  • The models are subjected to load by external forces, and they are radiated by circular polarised light.
  • An analyser analyses the light penetrating the body.
  • The experimental setup comprises the separate components: a light source, two linear polarising filters (polariser and analyser), two quarter-wave filters and a frame in which the models are attached and subjected to load.
  • The light source optionally permits coloured stress patterns with white light or a light/dark representation with monochromatic light.
  • The polariser includes a polarising filter and a quarter-wave plate and generates circular polarised light.
  • Behind the model is a second quarter-wave plate (perpendicular to the first one), which is combined with a second polarising filter.
  • These form the analyser.
  • The filters are mounted on rotating bearings and fitted with angle scales.
  • Various polycarbonate models are mounted inside the frame.
  • A load application device applies bending, tensile or compressive load to the model through a spindle.
  • Stresses and strains occurring in the model are identifiable as bright spots, visualising the distribution of stress.
  • The order of the dark isochromats is analysed to determine the principal stress differential.
  • A wide selection of models such as notched bars, a wrench and a model-roller bearing or a rack-and-pinion is available as accessories.
  • These ensure the implementation of comprehensive experiments.
  • It is also possible to investigate your own models.

Technical Details:

Specification:

  • produce the mechanical stress curves through photoelastic experiments
  • 2 linear polarising filters (polariser and analyser)
  • 2 quarter-wave filters for generating circular polarised light
  • all filters have 360° angle scale and indicate the main optical axis
  • filters mounted on roller bearings and can be pivoted
  • white light produced by a fluorescent tube and two incandescent bulbs
  • monochromatic light (yellow) generated by sodium vapour lamp
  • frame cross-members can be vertically adjusted
  • pressure or tensile forces generated by a threaded spindle
  • finished polycarbonate (PC) models available as accessories for the demonstration

Technical Data:

  • Light source:
    • lamp box with white diffuser
    • for white light:
  • 1 fluorescent tube TL-E 32W/33 (colour: 33)
  • 2 incandescent bulbs, candle lamp, frosted E14, 230V, 25W
  • for monochromatic light (yellow):
    • 1 sodium vapour lamp SOX35, 35W
  • Filter, mounted in glass, diameter: Ø 425mm:
    • 2 polarising filters (dark olive)
    • 2 quarter-wave filters (uncoloured)
  • Frame: W x H: 600x750mm
  • 230V, 50Hz, 1 phase
  • 230V, 60Hz, 1 phase; 120V, 60Hz, 1 phase
  • UL/CSA optional

Dimensions & Weight:

  • L x W x H: 800x600x750mm
  • Weight: approx. 50kg

Learning Objections/Experiments:

  • together with the accessories or your own models:
  • generate plane stress states in various models under load: bending, tensile load and compressive load
  • investigate stress distributions with linear or circular polarised light
  • interpret photoelastic fringe patterns: stress concentrations, zero points, neutral strands, areas of constant stress and stress gradients
  • graphically and computationally determine the stresses

Scope of Delivery:

  • 1 frame with load application device
  • 2 polarising filters
  • 2 quarter-wave filters
  • 2 filter mounts
  • 1 light source
  • 1 set of accessories
  • 1 set of instructional material

Features:

  • monochromatic or white light
  • models for specific problems can be prepared by the user.

Accessories:

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