Browsing by Author "Dababneh, Odeh"

Now showing 1 - 5 of 5
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    Application of an efficient gradient-based optimization strategy for aircraft wing structures
    (MDPI, 2018-01-04) Dababneh, Odeh; Kipouros, Timoleon; Whidborne, James F.
    In this paper, a practical optimization framework and enhanced strategy within an industrial setting are proposed for solving large-scale structural optimization problems in aerospace. The goal is to eliminate the difficulties associated with optimization problems, which are mostly nonlinear with numerous mixed continuous-discrete design variables. Particular emphasis is placed on generating good initial starting points for the search process and in finding a feasible optimum solution or improving the chances of finding a better optimum solution when traditional techniques and methods have failed. The efficiency and reliability of the proposed strategy were demonstrated through the weight optimization of different metallic and composite laminated wingbox structures. The results show the effectiveness of the proposed procedures in finding an optimized solution for high-dimensional search space cases with a given level of accuracy and reasonable computational resources and user efforts. Conclusions are also inferred with regards to the sensitivity of the optimization results obtained with respect to the choice of different starting values for the design variables, as well as different optimization algorithms in the optimization process.
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    Influence of high fidelity structural models on the predicted mass of aircraft wing using design optimization
    (Elsevier, 2018-05-26) Dababneh, Odeh; Kipouros, Timoleon
    This paper explores the necessary and appropriate level of detail that is required to describe the structural geometry of aircraft wings accurately enough to predict the mass of the main load-carrying wing structure to an acceptable level of accuracy. Four different models of increasing structural fidelity are used to describe the wingbox structure of a realistic real-world aircraft wing. The wingbox of the NASA Common Research Model served as a test model for exploring and analyzing the trade-off between the granularity level of the wingbox geometry description under consideration and the computational resources necessary to achieve the required degree of accuracy. The mass of metallic and composite wingbox configurations was calculated via finite element analysis and design optimization techniques. The results provided an insight into the competence of certain wingbox models in predicting the mass of the metallic and composite primary wing structures to an acceptable level of accuracy, and in demonstrating the relative merits of the wingbox structural complexity and the computational time and input efforts for achieving the required level of accuracy.
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    Multidisciplinary design optimisation for aircraft wing mass estimation
    (Cranfield University, 2016-04) Dababneh, Odeh; Kipouros, Timoleon; Whidborne, James F.
    The implementation of key technologies in the initial stages of the aircraft wing design process has always represented a substantial challenge for aircraft designers. The lack of reliable and accessible wing mass prediction methods ¬which allow assessment of the relative benefits of new technologies for reducing structural wing weight - is of significant importance. This necessitates the development of new and generally applicable wing mass estimation methods. This thesis aims to create a new framework for estimating the mass of metallic and composite transport aircraft wings via finite element multidisciplinary analysis, and design optimisation techniques. To this end, the multidisciplinary static strength and stiffness, dynamic aeroelastic stability, and manufacturing constraints are simultaneously addressed within an optimisation environment through a gradient-based search algorithm. A practical optimisation procedure is presented as part of the sizing optimisation process, with enhanced features in solving large-scale nonlinear structural optimisation problems, incorporating an effective initial design variable value generation scheme based on the concept of the fully stressed design. The applicability and accuracy of the proposed approaches is accomplished by conducting a number of case studies in which the wingbox structure of the public domain NASA wing - commonly referred to as the Common Research Model (CRM) - is optimised to produce a minimum mass design. The results of a case study examining minimisation of the mass of the CRM wingbox structures designed using four different models of increasing structural fidelity prove that the multidisciplinary design optimisation framework can successfully calculate the mass of realistic real-world aircraft wing designs. This provides an insight into the competence of certain wingbox models in predicting the mass of the metallic and composite primary wing structures to an acceptable level of accuracy, and in demonstrating the relative merits of the wingbox structural complexity models under consideration and the computational resources necessary to achieving the required degree of accuracy ... [cont.].
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    Multidisciplinary design optimization of the NASA metallic and composite common research model wingbox: addressing static strength, stiffness, aeroelastic, and manufacturing constraints
    (MDPI, 2025-06-01) Dababneh, Odeh; Kipouros, Timoleon; Whidborne, James F.
    This study explores the multidisciplinary design optimization (MDO) of the NASA Common Research Model (CRM) wingbox, utilizing both metallic and composite materials while addressing various constraints, including static strength, stiffness, aeroelasticity, and manufacturing considerations. The primary load-bearing wing structure is designed with high structural fidelity, resulting in a higher number of structural elements representing the wingbox model. This increased complexity expands the design space due to a greater number of design variables, thereby enhancing the potential for identifying optimal design alternatives and improving mass estimation accuracy. Finite element analysis (FEA) combined with gradient-based design optimization techniques was employed to assess the mass of the metallic and composite wingbox configurations. The results demonstrate that the incorporation of composite materials into the CRM wingbox design achieves a structural mass reduction of approximately 17.4% compared to the metallic wingbox when flutter constraints are considered and a 23.4% reduction when flutter constraints are excluded. When considering flutter constraints, the composite wingbox exhibits a 5.6% reduction in structural mass and a 5.3% decrease in critical flutter speed. Despite the reduction in flutter speed, the design remains free from flutter instabilities within the operational flight envelope. Flutter analysis, conducted using the p-k method, confirmed that both the optimized metallic and composite wingboxes are free from flutter instabilities, with flutter speeds exceeding the critical threshold of 256 m/s. Additionally, free vibration and aeroelastic stability analyses reveal that the composite wingbox demonstrates higher natural frequencies compared to the metallic version, indicating that composite materials enhance dynamic response and reduce susceptibility to aeroelastic phenomena. Fuel mass was also found to significantly influence both natural frequencies and flutter characteristics, with the presence of fuel leading to a reduction in structural frequencies associated with wing bending.
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    A review of aircraft wing mass estimation methods
    (Elsevier, 2017-11-08) Dababneh, Odeh; Kipouros, Timoleon
    In this paper, the current state of the art of aircraft wing mass estimation methods is reviewed. The phases of aircraft design and the development process are discussed. The open literature on the subject of wing mass estimation methods and their applications in the aerospace industry is discussed, and relevant data are presented to provide the reader with background information on the field. Special attention is given to classifications of wing mass estimation methods. Current challenges and technological difficulties in wing mass estimation methods are identified, and perspectives are drawn and used to propose several key ideas for future research in the field.