Distributed fiber optic sensors for monitoring cracks in civil infrastructure

Distributed Fiber Optic Sensors (DFOS) have exhibited unique strengths in monitoring cracks, providing real-time, spatially-distributed data that indicate structural integrity and support automation in the construction, operation, maintenance, management, and recycling of structures or structural components. This paper systematically reviews the scientific principles, influencing factors, technical methods, and applications of DFOS, aiming to enhance understanding and promote the applications of DFOS in automated monitoring of infrastructure. Fiber optic cables, installation methods, and sensing technologies are reviewed to promote construction practices. The reviewed contents extend to advancements in machine learning and digital twinning technologies for real-time, automated data processing, analysis, and visualization of the presence, location, and severity of cracks. Major challenges and emerging opportunities of utilizing DFOS are discussed to facilitate future research. This paper advances the understanding, development, and engineering applications of DFOS for monitoring cracks toward intelligent digitalization and automation of civil infrastructure.