&nbsp;Abstract submitted for the International mechanical Engineering Conference &amp; Exposition 2021Damage Tolerance Analysis of Wing Fuselage Interface in BWB Aircraft DesignAshok K Bakshi &amp; B Dattaguru&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; School of Aerospace Engineering, Jain deemed to be University&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Bengaluru, India&nbsp;&nbsp;&nbsp;A b s t r a c tAs the conventional aircraft manufacturing based on tube and wing concept came to a design saturation stage, aircraft industry is looking for totally new efficient configurations. In this regard the BWB (Blended Wing Body) aircraft offers a paradigm shift in the design of aircraft. This design provides aerodynamically efficient, low carbon emission environmental friendly benefits and can adopt advanced technologies like laminar flow, jet flaps and distributed propulsion, ease of flight control and others to mention a few. However, despite these benefits, the BWB is yet to be produced for commercial use due to several challenges. Now air travel business faced a great disruption due to grounding and affected wide bodied aircrafts production and produce multi-role aircrafts.&nbsp; This paper tried to bring out an alternative proposition in BWB aircraft design highlighting design challenges that have hindered the actual production of a viable BWB passenger aircraft of 300 passenger capacity with multi-role cargo option of equivalent payload. Even though the fully composite BWB concept is three decades old, it has not gone into production due to curing issues related to product quality and reliability of composite material apart from high costs in damage tolerance design, service repair and environmental hazard issues arising after disposal.&nbsp;Hybrid design using Metal and CompositesThe present study finds that to obtain benefits and reduce the deficiencies a combined metallic and composite material construction strategy may be opted, where a major portion of structure, the fuselage is metallic and wing and control surfaces can be of composite construction. This hybrid design option avoids large wing or fuselage made out of fully composite material, which needs huge autoclaves for curing and risk of manufacturing flaws. In BWB configuration the fuselage produces major amount of lift than the wings which can be of metallic which can be recycled after service life. Here wing size&nbsp; is&nbsp; smaller than fuselage and hence can be made out of composite material with co-bonded and co-cured manufacturing technology, ensuring better product quality and reliability&nbsp;&nbsp;Results of damage tolerance analysisThe damage tolerance analysis of the wing-fuselage integration is investigated using indigenously developed software FFModule to evaluate the tolerance of cracks at the wing root, which is designed with split opening mouth spar termination, at the fuselage interface from leading to failure. The FE analysis of the wing root carried out using NASTRAN software, shows a significant difference in magnitude between the stresses obtained in the skin at the wing root and those in the spar web. A significant proportion of the shear stresses in the spar web are transferred to the web root area. The resultant stresses in the spar web at the split opening mouth termination, are hence lower than those in the skin. The conclusion drawn from the results is that the skin is the more critical part at the wing root. The life of a crack occurring in the spar web would therefore be expected to be significantly greater than in the skin at the wing root. This implies that any inspections set at the required frequency for a skin location would be adequate for the spar location. There are three aspects to damage tolerance, namely; fatigue crack growth, residual strength at limit load and schedule for inspection. The damage tolerance capability of the proposed wing design was assessed by a crack growth assessment and residual life assessment using the two-bay crack criterion at the critical skin location. The FE assessment of the wing root assembly indicated that the skin is the more critical component at the wing root, compared to the open mouth spar termination at the fuselage attachment location.

Damage Tolerance Analysis of Wing Fuselage Interface in BWB Aircraft Design

Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2021/volume/85543

ASME 2021 International Mechanical Engineering Congress and Exposition (IMECE2021)

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