Differential interferometry for real-time measurement in high cycle fatigue metal testing

0451172 - ÚPT 2016 NL eng C - Conference Paper (international conference)
Lazar, Josef - Holá, Miroslava - Hrabina, Jan - Číp, Ondřej
Differential interferometry for real-time measurement in high cycle fatigue metal testing.
Photomechanics 2015. Book of Abstracts and Program. Delft: Delft University of Technology, 2015, s. 64-65.
[Photomechanics 2015. Delft (NL), 25.05.2015-27.05.2015]
R&D Projects: GA ČR GB14-36681G; GA TA ČR TA02010711; GA TA ČR TA01010995; GA TA ČR TE01020233; GA MŠMT(CZ) LO1212; GA MŠMT ED0017/01/01
Institutional support: RVO:68081731
Subject RIV: BH - Optics, Masers, Lasers

We present an interferometric method for measurement of strain induced deformation of metal samples in experiments inducing high-cycle fatigue. The motivation is to get real-time information about the deformation of a metal sample under test, its elongation imposed by fast vibrating actuator. The measuring setup was designed to measure only the deformation of the sample in a differential measuring configuration. The measurement technique uses laser interferometry, able to detect the absolute value of the displacement with a link to the fundamental etalon of length with nanometer resolution. The fast vibrations of the sample needed a design of a high-bandwidth detection chain and signal processing of the interference signal. A new concept of a compact differential interferometer is presented which compensates for small tilt of the reflecting surfaces in both reference and measuring paths and thanks to coaxial configuration is free from Abbe errors.
Permanent Link: http://hdl.handle.net/11104/0252366