Damage evaluation results of a hybrid pinned single-lap-shear joint by acoustic methods using a multi-method SHM system

Description

Large civil aircraft must adhere to stringent design criteria, including damage tolerance, for flight safety. Despite the potential of adhesive bonding for joining components, confidence remains limited, leading to the prevalent use of rivets and bolts. This persists despite advancements in material combinations and the weight penalties associated with conventional joining techniques. To tackle the challenges of classical structural bonding, metallic pins produced through additive manufacturing can be used to reinforce adhesive joints between metal and fiber-reinforced polymers (FRP), creating pinned hybrid joints. These pins improve strength and damage tolerance. However, uncertainties form material and manufacturing processes remain. Structural health monitoring (SHM) can help reduce uncertainties and ensure the integrity of pinned hybrid joints. The talk presents results of a new multi-method SHM concept for pinned hybrid joints that uses piezoelectric wafer active sensors for the application of several acoustic methods and electric contacting of the joint for the application of resistance-based methods. The acoustic methods, namely the electromechanical impedance, the guided waves, and the acoustic emission method are realized in a laboratory SHM system by the same sensors using a self-made Arduino-based switching unit. Consequently, the cabling and the measurement equipment effort is small and measurements can be used to verify each other, thus, increasing the reliability of damage evaluation results. Furthermore, different self-sensing methods could be implemented to ensure the reliability of the measurement system. The latest acoustic-based results of the multi-method SHM system applied to an extremely low-cycle tension-tension test are presented, discussed, and validated with the results of a digital image correlation system. Advantages and disadvantages of the different acoustic methods are discussed and conclusions for future work are presented.

Period	18 Sept 2024
Event title	36th Conference of the European Working Group on Acoustic Emission (EWGAE 2024)
Event type	Conference
Location	GermanyShow on map