Landing Gear Fatigue Damage Detection and Tracking Using MWM-Arrays

ABSTRACT: The high-strength steels (HSS) used for landing gear components have a relatively low fracture toughness, and, therefore, once a crack is formed in a HSS component, it may grow rapidly, potentially leading to catastrophic failure of the part and potential loss of the aircraft. This SBIR program will demonstrate the feasibility of using JENTEK Sensor's MWM-Array flexible eddy current technology to detect early stage fatigue damage in high-strength steels used for landing gear. In Phase I, fatigue tests will be performed on HSS coupons to demonstrate the MWM-Array's capability to image precrack and/or early crack formation based on changes in an electrical property (e.g., magnetic permeability) of the HSS. Early fatigue damage identified by MWM-Array imaging will be verified using methods such as scanning electron microscopy and fractography. A simple scanning fixture will be adapted for MWM-Array imaging of a landing gear component to show feasibility of scanning on an actual landing gear component. BENEFIT: Landing gear is a critical, non-redundant system in military and commercial aircraft. The capability to inspect for early fatigue damage with the MWM-Array technology is expected to enable reduction in inspection frequency, increased margins of operational safety, transitioning to a condition-based maintenance paradigm and the corresponding life extension of landing gear components. These benefits could be achieved on both military and commercial landing gear and any other application with high value HSS components. The technologies developed will be readily adaptable to rotorcraft, ship, and ground vehicle drive trains, and ferrous steel structural elements. Because maintenance and support tasks account for the largest portion of total ownership costs, significant savings can be realized over the lifecycle of these systems with condition based maintenance.