{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T19:09:07Z","timestamp":1777576147905,"version":"3.51.4"},"reference-count":32,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2021,1,5]],"date-time":"2021-01-05T00:00:00Z","timestamp":1609804800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"BMWin program \u201cZentrales Innovationsprogramm Mittelstand-ZIM\u201d","award":["ZF4314601WM6"],"award-info":[{"award-number":["ZF4314601WM6"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In this article, a non-contact laser Doppler strain sensor designed for fatigue testing with the resonance-testing machine is presented. The compact sensor measures in-plane displacements simultaneously from two adjacent points using the principle of in-plane, laser-Doppler vibrometry. The strain is computed from the relative displacements divided by the distance between these two points. The optical design, the mathematical model for estimating noise-limited resolution, the simulation results of this model, and the first measurement results are presented. The comparison of the measurement results of our sensor with the results of a conventional strain gauge shows that our design meets the measurement requirements. The maximum strain deviation compared to conventional strain gauges of the laser-Doppler extensometer is below 4\u00d710\u22125 in all performed experiments.<\/jats:p>","DOI":"10.3390\/s21010319","type":"journal-article","created":{"date-parts":[[2021,1,5]],"date-time":"2021-01-05T21:18:57Z","timestamp":1609881537000},"page":"319","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["A Contactless Laser Doppler Strain Sensor for Fatigue Testing with Resonance-Testing Machine"],"prefix":"10.3390","volume":"21","author":[{"given":"Fangjian","family":"Wang","sequence":"first","affiliation":[{"name":"Institute of Electrical Information Technology, Clausthal University of Technology, Leibnizstr. 28, D-38678 Clausthal-Zellerfeld, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Steffen","family":"Krause","sequence":"additional","affiliation":[{"name":"SincoTec Test &amp; Engineering GmbH, Innovationspark Tannenh\u00f6he, Freiberger Str. 13, D-38678 Clausthal-Zellerfeld, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Joachim","family":"Hug","sequence":"additional","affiliation":[{"name":"SincoTec Holding GmbH, Innovationspark Tannenh\u00f6he, Freiberger Str. 13, D-38678 Clausthal-Zellerfeld, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christian","family":"Rembe","sequence":"additional","affiliation":[{"name":"Institute of Electrical Information Technology, Clausthal University of Technology, Leibnizstr. 28, D-38678 Clausthal-Zellerfeld, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,1,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Keil, S. 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