A portable residual stresses measurement device using ESPI and a radial in-plane interferometer

摘要

This paper presents a new kind of double illumination interferometer used for radial in-plane displacement measurement through electronic speckle pattern interferometry (ESPI). Some characteristics and implementation details are discussed. This new interferometer is used for residual stresses measurement combining, in a very efficient way, the blind hole method and the in-plane radial displacement measurement by ESPI. Algorithms and implementation characteristics are also discussed. A portable device was built to measure residual stress outside the optical bench. Early results show a measurement performance comparable to the conventional blind hole method using strain gages. Measurement time is almost one order less than the strain gage based measurement system.