Engineering topics

William C Wilson

Publications and source records attributed to William C Wilson.

3 records

NASA NTRS2024

Material Inspectability Assessment Related to Lunar Construction Technology Development

For the building of lunar structures on the Moon using lunar regolith-based construction materials, ensuring their structural integrity and employing methods optimal for such tasks is crucial. In this technical memorandum (TM) the detectability of simulated void defects in a cementitious-based lunar construction material is compared between different nondestructive evaluation (NDE) methods, especially methods which have potential to be developed into space qualified instruments. Primarily, simulated voids, introduced during fabrication as foam spheres, were used for this evaluation. Furthermore, smaller, unintended void defects were used to assess the detectability. The results highlights trade-offs between the NDE methods in terms of detection limit, correct size indication, penetration depth, and potential for reduction in size, weight, and power (SWaP).

Nondestructive Evaluation↗

NASA NTRSDate not supplied

Structural Health Monitoring of Vertical Lift Structures Operating in an Urban Environment

Verifying the structural integrity of aeronautical vehicles is of critical importance for the safety of passengers and crew. When operating in a densely populated urban area, pedestrian safety and collateral damage to buildings and other infrastructure also become important concerns. Damage modes, including fatigue from an increased frequency of take-off and landing cycles and a higher probability of impacts from bird strikes, also pose different failure risks as compared to commercial long-haul aircraft and thus require a change in structural health monitoring philosophy. This presentation will review the state of the art in structural health monitoring with an eye toward applications for vertical lift systems operated in the urban environment. Structural health monitoring methods including eddy current, fiber optic, ultrasonic plate wave, surface acoustic wave and electrical impedance tomography will be explored for use in on-board monitoring of impact and overstrain events as well as damage detection and characterization. Infusion of the data into an early warning system to help ensure damage will not propagate to failure during flight will also be discussed.

Russell A Wincheski↗

NASA NTRSDate not supplied

Spoof Plasmon Polaritons for NDE Applications an Experimental Demonstration

NASA is exploring the use of microwave spoof plasmon polaritons to detect defects in metallic structures. This work investigates the detection of simulated defects in the form of aluminum wires as small as 1.6 mm diameter and 2mm long that are placed in a grooved aluminum test article. The inclusions simulate manufacturing defects, and the sum of the delta impedance is shown to increase with increasing volume of added metal. A threshold value of 50Ω has been proposed for defect detection. In addition to detecting defects, the technique also estimates the volume of the defect.

Microwave↗