Monitoring concept for the propagation of compressive fatigue in externally prestressed concrete beams using digital image correlation and fiber optic sensors

Abstract

The fatigue of concrete has been the subject of research for many years, and yet, there are still open questions. In particular, the fatigue-induced damage evolution accompanied by a stress redistribution process propagating through the concrete structure is still not fully understood. So far, there are only few experimental studies addressing the fatigue propagation through a material zone occurring, for example, in beams with a pulsating, nonuniform stress profile. To investigate the influence of such stress configurations on the material and structural degradation process, a measuring concept has been developed combining digital image correlation, fiber optic sensors, and conventional strain gauges. The presented experiments visualize the propagating fatigue degradation in the compression zone of prestressed concrete beams subjected to fatigue loading. Based on the developed measurement concept, the quantitative foundation for a comprehensive validation of design rules and material models accounting for concrete fatigue can be significantly extended.

Crack monitoring on concrete structures: Comparison of various distributed fiber optic sensors with digital image correlation method

“…Due to its ability of measuring strains continuously along the distributed fiber optic sensor (DFOS), fiber optic sensing technology has recently received a lot of attention in the field of experimental research 16–18 and SHM 19,20 . By integrating DFOS into the concrete, it is possible to gain valuable insights into the specimen 21–23 .…”

Neue Perspektiven auf das Querkrafttragverhalten von Stahlbetonbauteilen ohne Querkraftbewehrung

“…Faseroptische Messverfahren sind bereits seit Ende der 1980er‐Jahre bekannt und eröffnen ein breites Anwendungsspektrum im Bereich des Bauingenieurwesens. Für eine vertiefte Darstellung wird auf [25–28] verwiesen. Im vorliegenden Beitrag wurden die Dehnungen entlang der Längsbewehrung auf der Ober‐ und Unterseite mit jeweils einem faseroptischen Sensor erfasst.…”

Untersuchung des Verbundverhaltens von CFK‐Spannlitzen in Beton mit faseroptischen Sensoren

“…Bessere Messergebnisse lassen sich mit der optischen Speckle-Messung [21,22] breitenerfassung [32], Dehnungen der Bewehrung [33] auf Stahl- [34] und Spannbetonbauteilen [23,35].…”