| title: | NONLINEAR INTEGRATED PHOTOELASTICITY |
|---|---|
| reg no: | ETF4972 |
| project type: | Estonian Science Foundation research grant |
| subject: |
1.3. Physics 2.3. Mechanics |
| status: | completed |
| institution: | Institute of Cybernetics at Tallinn Technical University |
| head of project: | Hillar Aben |
| duration: | 01.01.2002 - 31.12.2005 |
| description: | Basic optical equations of integrated photoelasticity are nonlinear. However, until now in practical applications of this method the linear approximation has been used assuming either that birefringence is weak or that the principal stress axes are about constant. In many practical applications of integrated photo-elasticity, including residual stress measurement in glass articles, these assumptions are not valid. In this research project the possibilities of correct formulation of the inverse problem of integrated photoelasticity will be investigated taking into account the nonlinear relationships between the parameters of the stress field and the measurement data. This problem belongs to the class of ill-posed problems. One possibility to solve the inverse problem lies in minimizing the deviation function which expresses the deviation of the experimental results from those calculated using predetermined parameters of the stress field. Another possibility to solve the inverse problem is related to the application of the genetic algorithms. Construction of artificial neural networks will also be considered. Besides axisymmetric stress fields, specimens of arbitrary 3D geometry will also be considered including also photoelastic measurements in a magnetic field (magnetophotoelasticity). Since the experimental data is usually insufficient for the determination of all the stress components, construction of hybrid mechanics algorithms for complete stress analysis will be considered. The results will be published in scientific journals and implemented in algorithms and software for the interpretation of the measurement results which are applied by the measurement of residual stresses in various glass articles. Automatic measurement apparatus will also be constructed. |
| project group | ||||
|---|---|---|---|---|
| no | name | institution | position | |
| 1. | Hillar Aben | Tallinn Technical University Institute of Cybernetics | Laboratory head | |
| 2. | Leo Ainola | -"- | Sen. res.fellow | |
| 3. | Johan Anton | -"- | PhD student | |
| 4. | Andrei Errapart | -"- | Postgraduate student | |
| 5. | Ants Rumberg | -"- | Mechanic | |
| 6. | Pilvi Veeber | -"- | Secretary | |