Dynamic Fracture Behavior of Fiber Reinforced Polymer–Reinforced Concrete Beams Under Different Initial Static Loads

ABSTRACT To investigate the dynamic fracture behavior of fiber reinforced polymer (FRP)–reinforced concrete structures, the dynamic fracture tests under different initial static loads were conducted in this paper, and using acoustic emission (AE) and digital image correlation (DIC) techniques for real‐time monitoring. The test results indicate that while the initial static load has negligible influence on crack initiation load and toughness, it significantly affects other fracture parameters. The crack resistance load, ultimate load, crack extension length, crack resistance toughness, and instability toughness exhibit an exponential decay relationship with increasing initial static load. The FPZ length increases with increasing initial static load. The AE analysis revealed signal variations correlated with internal damage progression, with lower static loads promoting crack propagation along the beam span. The DIC‐derived strain fields confirmed horizontal strain and displacement as reliable crack indicators, remaining insensitive to initial static load changes at the ultimate load point. These findings provide a predictive model for FRP‐reinforced concrete dynamic fracture behavior.