Publications
Haris Ali Khan, Sharjeel Salik, Shahab Uddin
The present invention discloses a novel Lock-In Thermography-based scanning method to efficiently detect subsurface defects related to rivets in aircraft structures. We have employed a customized thermographic device comprising a thermal camera, heating source, and synchronized control circuitry, for scanning while the method includes a post-processing operating system. The post-processing operating system is developed to accurately detect rivet-related defects from raw thermal images by augmenting multiple image processing techniques, including Spatial Gradient and Discrete Wavelet Transform. The invention offers an effective and efficient solution for detecting rivet-related subsurface defects in aircraft, enhancing safety and maintenance protocols.
Haris Ali Khan, Sharjeel Salik, Shahab Uddin, Ali Javaid, Taha Ali Khan, Zia ul Islam
This research is focused on developing a novel Lock-In Thermography-based scanning system to detect subsurface defects in aircraft rivets. The proposed system included a customized thermographic device consisting of a thermal camera, heating source, synchronized control circuitry, and post-processing software utilizing the Discrete Wavelet Transform technique, augmented by spatial gradient and mean filtering methods. To validate the developed system, a two-pronged hierarchical approach was adopted. The detection scheme for looseness and internal cracks in rivets was first developed and refined in a lab environment. After successful trials on lab samples, the scheme was further employed in different areas of actual aircraft. A total of 751 rivets were scanned for looseness and internal cracks, and a very promising detection rate was observed, confirmed through visual inspection and microscopic analysis. The developed setup can be further extended to other sub-surface defects such as corrosion and other structural non-homogeneities.
Waseem Ahmad, Haris Ali Khan, Sharjeel Salik, Hafiz Qasim Ali, Sara Khushbash, Zahid Ahmed Qureshi
The demand for lightweight, high-strength materials in the automotive industry has led to the exploration of novel manufacturing techniques. This research delves into the feasibility of creating multi-material composite-metal structures through Fused Deposition Modeling (FDM), emphasizing the optimization of interfacial adhesion between composite and metal layers. The study adopts a systematic and hierarchical approach, commencing with the initial optimization of a fiber-metal structure comprising Carbon Fiber Reinforced Polymer (CFRP), Steel, and additional CFRP layers. Key printing parameters, namely extruder temperature, nozzle temperature, and bed temperature, are optimized using both qualitative and quantitative quality criteria. Qualitative evaluations involve scrutinizing the print quality, layer adhesion, and overall structural integrity, while quantitative criteria encompass mechanical testing and analysis.