A Study on Prediction of Fatigue Crack Propagation Life Using MFC Sensors

One of the most important tasks in offshore and ship structures is to avoid structural failure due to defects induced by cyclic loading and structural deterioration. While the detection technology for such flaws is essential in order to ensure the integrity of structures, it is difficult to identify and measure such defects in real time with sufficient reliability. In this regard, various structural health monitoring (SHM) techniques have been developed for detecting defects and damage from many research communities. One of the key parameters in structural integrity assessment (SIA) is a precise estimation of the stress intensity factor (SIF). The SIF is used for estimating the fatigue crack propagation life based on linear elastic fracture mechanics (LEFM). In this study, the SIF of a simple test specimen is measured in real time using a macro-fiber composite (MFC) sensor. MFC sensor is a high-performance smart material used both for actuator and sensor offering good flexibility and reliability. This study examines the feasibility of MFC sensors for an SHM application with particular attention to fatigue crack monitoring. Finally, the fatigue crack propagation life calculated by an MFC sensor is compared with experimental results.