X-ray Computed Tomography Inspection Research Articles

Simulation of a liquid propellant rocket engine manufacturing assembly line utilizing the PFS/PN methodology

The system addressed in this paper pertains to an assembly line for liquid propellant rocket engines equipped with turbopump. The challenge involves automating the process of metal 3D printing for the turbopump and combustion chamber, followed by heat treatment for stress relief, X-ray computed tomography inspection, and the subsequent movement of components throughout the factory. To achieve this, the PFS/PN methodology was employed to facilitate a detailed analysis of the system, ensuring control over its inputs and outputs. The system was simulated using the ProModel Discrete Event Simulator, and the results were scrutinized, indicating the robustness of the simulation. Following the Ladder methodology, programming for Programmable Logic Controllers was also developed.

Azimuthally Scanned Angled-Beam Pulse-Echo Ultrasound for Characterization of Impact Damage in Composites

Abstract Characterization of barely visible impact damage (BVID) in polymer matrix composites (PMCs) is necessary to use slow crack growth damage tolerance models and evaluate remaining life of PMC components. Azimuthally scanned angled-beam pulse-echo ultrasound is investigated as a complimentary technique to normal incidence ultrasound inspection of BVID in PMCs to characterize delamination fields. It is found that there is a correlation between signals present in the azimuthally scanned angled-beam pulse-echo ultrasound C-scans and transverse cracks seen in X-ray computed tomography inspection. These transverse cracks are not readily identifiable as transverse cracks in normal incidence C-scan inspection.

XCT inspection in bonded aircraft repairs for composites

As bonded composite repairs are gaining importance for modern civil aircraft, it is necessary to investigate such repairs in detail under relevant environmental conditions. In this work, X-ray computed tomography (XCT) was performed on bonded repairs for carbon fiber (CF) reinforced epoxy matrix composites before and after cyclic conditioning between dry/cold and hot/wet conditions. In detail, high resolution XCT scans in absorption contrast (AC) mode as well as Talbot-Lau grating interferometer (TLGI)-XCT scans to obtain additional differential phase contrast (DPC) and dark-field contrast (DFC) modalities were performed. The repair bonds' constituents could be identified by the high resolution XCT scans. Additional information about fiber alignment, at least of the fiber bundles, could be extracted from the TLGI-XCT scans. In order to gain detailed information on certain specimen features, specimen dimensions were reduced for additional high resolution XCT scans.