Experimental analysis of stress fields of rotating structural elements by means of reflection photoelasticity.

The subject of this paper is an experimental stress analysis of a rotor with a symmetrical arm end and a rotor with an asymmetrical arm end. The main aim of this paper is to test the application of the Harmonic Star Method software developed by the authors. This software analyzes stress states in rotating structural elements. The stress state of the analyzed rotors is caused by centrifugal forces. The experiment was carried out by means of reflection photoelasticity, and the experimental solution was focused on periodical dynamic effects, which required the use of stroboscopic white light. The resulting principal normal stresses were compared with stress values, which were obtained by analytical calculations and by numerical means of the finite element method.

Methodology of contact stress analysis of gearwheel by means of experimental photoelasticity.

The subject of this paper is the analysis of contact stresses that occur between the teeth of a gear. The analysis was carried out by means of reflection photoelasticity, which is an experimental method rarely used in this field. Contact stresses assessed in the experiment are compared with values assessed through an analytical calculation while using the Airy stress function or Hertzian relations.

Application of the harmonic star method in photoelastic separation of principal stresses.

This paper deals with automation of an experiment process by means of photoelasticity on the condition that only information which was previously collected by identification of isochromatic fringes is used. The analysis of this issue pointed to Poisson's and Laplace's equations. These equations were solved through the harmonic star method. The automation of an experiment was based on the development of a noncommercial program for processing of data which had been collected during photoelastic measurements. In addition, the program was used for verification of these measurements and comparison of measurement outcomes with results which were gained by the finite element method (FEM). Such a program enabled us to measure stresses in a certain point of the examined surface and, at the same time, separate these stresses, that is, determine the magnitude of individual stresses. A data transfer medium-a camera-was used to transfer the picture of isochromatic fringes directly into a computer. The chosen procedure of solving and evaluating the experiment provided us with reliable outcomes comparable to results gained by FEM.