Product Model：LLH-100 Digital Photoelasticimeter

       Photoelastic method is an optical method for measuring stress。It uses transparent material with birefringence properties make structure, with the practical engineering components or parts geometry similar model, similar to the actual components and load applied on the model, can be calculated according to the photoelastic fringe stress model boundary and interior points, then the similarity theory is converted into the stress on the original, its accuracy can meet the requirement of engineering design。Photoelastic method can used to stress component measurement geometry and loading conditions are more complex, especially can measure other method to solve the stress concentration and the internal stress problems。Thus, it’s in favor of  the academic and engineering fields。Especially ，Photoelastic is an important part of mechanics experiment teaching in institutions of higher learning.
      LLH-100 LED Digital photoelastic instrument has the advantages of compact structure, convenient operation, especially suitable for high school mechanics experiment teaching。The photo elastic instrument using LED light source, can produce the stable white and red, green, and blue diffuse light, the light source and the polarizer directly connected, prevent other miscellaneous effects of light on experiment, greatly reducing the environmental requirements for use。The culture of the photoelastic apparatus also especially pay attention to the students' practical ability, reasonable design is more convenient for students to operate。Analysis of the experimental students can do it yourself for beam bending test, hole edge stress concentration coefficient measurement, different notch stress concentration phenomenon。It is beneficial for the students to deepen the teaching content of mechanical understanding。 

The main technical indicators：

1.Aperture：100mm

2.Linear polarizing filter effective diameter：100mm

3. 1/4 wave plate effective diameter：100mm

4. Load：0～50kg

5. light source：LED White light source and red ,green, blue Three kinds of light source

6.Image collection:  import Color video camera

7. mechanical sensor and Digital Indicator

8. The loading frame design simple（Has applied for a patent ），the dimensions of the instrument was significantly reduced, and can rotate freely observed isochromatic and isoclinic line.

Principle diagram：

                  The principle diagram of the photoelastic apparatus light path

                      Monochromatic light stripe / Mixed light stripe

Experimental schematic And application scope:

        The stress birefringence properties, transparent plastic model can be made in engineering machinery parts, and then simulate the stress components, observation, analysis of color and pattern of polarized light interference, so as to determine the stress distribution within part.

Disk under diametral compression experiment:

U piece of bending combination experiment

  

Pure bending beam experiment：

NOTE: Photoelastic method is intuitive, can directly display the stress concentrated area, and provide the accurate stress concentration values;It not only can get convenient stress but also the internal stress of the  structure . Especially this method is not constrained to the shape or load; it also can analyze the engineering structure stress.