Abstract
Even though carbon fiber reinforced plastic (CFRP) has remarkable mechanical properties, invisible or barely visible damage significantly degrades the strength of CFRP, restricting design space of CFRP aircraft structures. In this context, several structural health monitoring (SHM) technologies have been developed. If detected damage can be repaired by using rapid cure CFRP patch immediately after its occurrence, CFRP structures can be designed to tolerate larger damage, and thus more lightweight and adaptable aircraft structures may be realized. However, damage size, position, and type estimated by SHM systems are not absolutely accurate. Hence, this study experimentally and numerically investigated effects of the uncertainty about detected-damage information on the strength of repaired parts. Simulated impact or lightning damage was introduced in strip specimens, and tensile tests were conducted using them after repairing. It was shown that the strength requirement of the repaired part can be fulfilled by deciding the size of the CFRP repair patch in consideration of the uncertainty about the damage information. Furthermore, required capability of an impact damage detection system combined with the rapid repair method was identified.
