Measuring Residual Concrete Strength After Penetration and Blast

During Phase I, IFOS demonstrated the feasibility of using embedded optical Fiber Bragg Grating (FBG) sensor networks to measure resistance to penetration (for subsequent weapons) in concrete damaged by a weapon projectile. FBG sensors are well suited for monitoring dynamic strain in concrete structures due to their small size, low cost, ability to be embedded internally or surface mounted; and their multiplexing capabilities for increasing the number of sensors. During Phase II, the unique IFOS team of experts will develop and test a robust, ultra-high-speed, low-cost, real-time remote monitoring system for concrete based on embedded optical FBG sensor networks. The system will make use of multiple color-coded FBG sensors can be cascaded in a single fiber to form a natural “self-contained” sensor network, providing synchronized and correlated sensing. The sensors will make precise measurements of sequence of impact and timing of penetration, while smart algorithms make correction and determining given penetration depths for varying structure densities according to real-time data. This system developed in Phase II will be validated during live-fire tests on 10’x10’x6’ concrete targets with 0.3 scale BLU-109 penetrators. The proposed system will provide significant cost-savings over current techniques, while improving measurement accuracy.