Dynamic photoelasticimeter with rotating birefringent element
US4179217A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 14, 1978 |
| Grant date | Dec 18, 1979 |
| Priority date | — |
| Expiry date | Feb 14, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/23
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This invention relates to a dynamic photoelasticimeter with a rotating birefringent element. It comprises a laser, a birefringent plate rotatable at a constant speed, a model to be studied, a circular analyzer and a photodetector supplying signals at its output having frequency components of 2.omega. and 4.omega.. The ratio of the amplitudes of these signals supplies an indication of the phase shift .phi. (t) contributed by the model, and the phase of the signal of the frequency 4.omega. contributes information as to the orientation .theta. of the axes of the model at the point in question. The present invention provides a particularly simple and accurate dynamic photoelasticimeter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.