Muhammad Anas Athar

Technische Universitat Braunschweig Germany

Abstract Title:Electron beam perforation and joining of metallic suction sheets with pre-applied adhesive to core structures in HLFC suction panels

Biography:

Muhammad Anas Athar is a research assistant at the Institute of joining and welding of the TU Braunschweig, Germany specializing in experimental, numerical and simulative methods employed to lightweight materials. He received his Bachelors of Engineering (BE) in mechanical from NED University of Engineering and Technology, Karachi and completed his Masters of Science (M. Sc.) in Computational Sciences in Engineering (CSE) at the TU Braunschweig. He is currently working for a project in an excellence cluster at TU Braunschweig namely SE2A (Sustainable Energy Efficient Aviation) which aims at developing ideas and solutions for a more climate-friendly aviation of the future.

Research Interest:

Hybrid Laminar Flow Control (HLFC) suction panels are employed in aircraft design to reduce drag and improve fuel efficiency, contributing to sustainable aviation. These panels feature suction surfaces with micro-perforations that draw air from the boundary layer, delaying the transition from laminar to turbulent flow and significantly reducing drag. A key challenge in HLFC panel design is preventing blockage of micro-holes. The perforation technique and the bonding method for joining suction surface to core are the critical factors. While laser drilling is commonly used, it is slow and generates thermal effects, leading to residual stresses, burning and damage of the surface. Electron beam drilling, in contrast, is faster and generates minimal heat, reducing the risk of damage to the surfaces. Also, the application of adhesive and bonding of suction surfaces after perforation leads to blockages of the micro-holes which has to be avoided. Hence, this study explores electron beam drilling of metallic facesheets pre-coated with aerospace-grade adhesive films. Two adhesive films are mechanically characterized for tensile and bonding strength using tensile and peel tests. The adhesives are applied to the metallic sheets, partially cured in a vacuumed autoclave and the metallic sheets are then perforated with electron beam drilling. Three types of Triply Periodic Minimal Surface (TPMS) cores namely gyroid, primitive and diamond are used. After perforation, bonding of the suction surfaces to the core structures takes place again in the autoclave. The sandwich panels are analyzed under a Scanning Electron Microscope (SEM) to evaluate micro-hole blockages and morphology. Flow meter tests are performed to assess airflow properties while compression tests determine the load-bearing capacities of the adhesives, TPMS cores and overall structural integrity of the panels. This approach aims to optimize HLFC panel design by addressing key challenges in micro-hole blockages, improving aerodynamic performance and ensuring structural reliability