| title: | Photoelastic tomography |
|---|---|
| reg no: | ETF6881 |
| project type: | Estonian Science Foundation research grant |
| subject: |
1.3. Physics 2.3. Mechanics |
| status: | accepted |
| institution: | Institute of Cybernetics at Tallinn Technical University |
| head of project: | Hillar Aben |
| duration: | 01.01.2006 - 31.12.2008 |
| description: | Most of the methods of experimental mechanics (strain gauges, moire, holography, speckle etc) permit measurement of displacements, deformations and stresses only at the external surface of test objects. No methods for non-destructive measurement of stress fields in three-dimensional objects exist. Traditional tomography considers only scalar fields and its direct application for the measurement of stress tensor fields is not possible. The authors of this proposal have shown that using linear approximation of the equations of integrated photoelasticity the problem of determining the stress tensor field can be decomposed into several problems of scalar field tomography for single stress components. Thus principal possibility of photoelastic tomography has been proved. At the same time, tomography of the tensor field is considerably more complicated than scalar field tomography and a complex of investigations is to be carried out to make photoelastic tomography an efficient tool of experimental mechanics. The algorithms of the inverse problem of classical tomography will be analysed from the point of view of their suitability for photoelastic tomography. Numerical experiments are carried out with the aim to clarify the optimum number of projections and the sensitivity of the solution to measurement errors. Application of continuous functions (polynomials, splines, Fourier expansions etc) in stress field tomography is investigated. The domain of application of the linear approximation of photoelastic tomography will be established and possibilities to formulate photoelastic tomography in non-linear approximation will be investigated.Measurement technology of photoelastic tomography will be developed (automatic rapid transmission polariscope, rotary stage for test objects etc). Main area of application of photoelastic tomography is residual stress measurement in glass articles of complicated shape. |
| project group | ||||
|---|---|---|---|---|
| no | name | institution | position | |
| 1. | Hillar Aben | Tallinna Tehnikaülikooli Küberneetika Instituut | ||
| 2. | Leo Ainola | |||
| 3. | Johan Anton | |||