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Dillinger, J.K.S. (author), Abdalla, M.M. (author), Meddaikar, M.Y. (author), Klimmek, Thomas (author)This paper presents an aero load correction strategy applicable to the static aeroelastic optimization of composite wings. The optimization framework consists of a successive convex subproblem iteration procedure, in which a gradient-based optimizer consecutively solves a local approximation problem. Responses are approximated as a linear and...journal article 2019
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Peeters, D.M.J. (author), Lozano, Gustavo Gonzalez (author), Abdalla, M.M. (author)A method to optimise the fibre angle distribution of variable stiffness laminates is proposed. The proposed method integrates a fibre angle retrieval step with a fibre angle optimisation procedure. A multi-level approximation approach is used in combination with the method of successive approximations. First, fibre angle retrieval is done by...journal article 2018
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Peeters, D.M.J. (author), Hong, Z. (author), Abdalla, M.M. (author)A way to approximate the compliance of composites for optimisation is described. A two-level approximation scheme is proposed inspired by traditional approximation concepts such as force approximations and convex linearisation. In level one, an approximation in terms of the reciprocal in-plane stiffness matrix is made. In level two, either...journal article 2018
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Wang, Z. (author), Turteltaub, S.R. (author), Abdalla, M.M. (author)This work is concerned with the development of a framework to solve shape optimization problems for transient heat conduction problems within the context of isogeometric analysis (IGA). A general objective functional is used to accommodate both shape optimization and passive control problems under transient conditions. An adjoint sensitivity...journal article 2017
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Wang, Zhen Pei (author), Abdalla, M.M. (author), Turteltaub, S.R. (author)In isogeometric shape optimization, the use of the search direction directly predicted from the discrete shape gradient makes the optimization history strongly dependent on the discretization. This discretization-dependency can affect the convergence and may lead the optimization process into a sub-optimal solution. The source of this...journal article 2017
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Peeters, D.M.J. (author), Irisarri, F.X. (author), Abdalla, M.M. (author)Modern composite structures o<br/>er two avenues of optimising performance. One, optimising a single stacking sequence over the structure leading to constant sti<br/>ness designs. Two, varying the sti<br/>ness over the structure. This may be achieved by dropping plies, changing the thickness, or by steering the fibres, changing the fibre angles....conference paper 2016
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- Peeters, D.M.J. (author), Abdalla, M.M. (author) conference paper 2016
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Peeters, D.M.J. (author), Abdalla, M.M. (author)Nonconventional laminates, as defined in this paper, are laminates where ply angles are not restricted to a finite set: for example 0, 45, −45 −45 and 90 deg. Removing this restriction, structural behavior (for example, postimpact behavior) can be significantly improved. Nonconventional laminates are made of straight or steered fibers leading to...journal article 2016
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Hong, Z. (author), Abdalla, M.M. (author)Optimisation algorithms used to automatically size structural members commonly involve stress constraints to avoid material failure. Therefore the cost of optimisation grows rapidly as the number of structural members is increased due to the corresponding increase in the number of constraints. In this work, an efficient method for large scale...conference paper 2016
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- Peeters, D (author), Abdalla, M.M. (author) journal article 2016
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Peeters, D.M.J. (author), Abdalla, M.M. (author)A method to optimise the fibre angle distribution of variable stiffness laminates is proposed. The proposed method integrates a fibre angle retrieval step with a fibre angle optimisation procedure. A multi-level approximation approach is used in combination with the method of successive approximations. First, fibre angle retrieval is done by...conference paper 2015
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Jeliazkov, M. (author), Sardar Abadi, P.M. (author), Lopes, C.S. (author), Abdalla, M.M. (author), Peeters, D.M.J. (author)A computationally efficient two-level design methodology is developed for the optimization of stiffened compression loaded panels having variable stiffness panels as their skin. In the first step extensive bay panel optimization is performed using a Rayleigh-Ritz energy method coupled with a specialized Genetic Algorithm. Results in agreement...conference paper 2015
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Wang, D. (author), Abdalla, M.M. (author)Grid-stiffened composite structures, where the skin is stiffened by a lattice of stiffeners, not only allow for significant reduction in structural weight but are also competitive in terms of structural stability and damage tolerance compared with sandwich composite structures. As the development of Automated Fiber Placement (AFP) technology...conference paper 2015
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Sardar Abadi, P.M. (author), Jeliazkov, M. (author), Sebaey, T.A. (author), Lopes, C.S. (author), Abdalla, M.M. (author), Peeters, D.M.J. (author)This paper presents the design procedure of a quasi-isotropic (QI) laminate employing dispersion of ply orientations. The goal is to improve damage resistance of a laminate under low velocity impact (LVI). The LVI is treated as a quasi-static loading and instead of a plate a laminated beam is considered. Therefore, this situation simplifies the...conference paper 2015
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Werter, N.P.M. (author), De Breuker, R. (author), Abdalla, M.M. (author)Over the years, wings have become lighter and more flexible, making them more prone to aeroelastic effects. Thus, aeroelasticity in design becomes more important. In order to determine the response of an aircraft to, for example, a gust, an unsteady aerodynamic model is required to determine the dynamic loads. The three most-commonly used...conference paper 2015
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Wang, D. (author), Abdalla, M.M. (author)There is a renewed interest in grid-stiffened composite structures; they are not only competitive with conventional stiffened constructions and sandwich shells in terms of weight but also enjoy superior damage tolerance properties. In this paper, both global and local structural instabilities are investigated for grid-stiffened composite panels...conference paper 2014
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Thuwis, G.A.A. (author), Abdalla, M.M. (author), Gürdal, Z. (author)One of the possibilities for the next generation of smart high-lift devices is to use a seamless morphing structure. A passive composite variable-stiffness skin as a solution to the dilemma of designing the structure to have high enough stiffness to withstand aerodynamic loading and low stiffness to enable morphing is proposed. The variable...journal article 2010
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Nagy, A.P. (author), Abdalla, M.M. (author), Gürdal, Z. (author)Thin-walled composite structures, typically modeled as Cosserat continua during the design phase, are of particular importance in aerospace and automotive applications. At the dawn of industrial scale adoption of advanced fibre placement technology, it became viable to better exploit the directional properties of composite materials. In the...conference paper 2010
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Khani, A. (author), Abdalla, M.M. (author), Gürdal, Z. (author)For a non-circular cylinder the radius of curvature changes around the circumference. Therefore for constant stiffness non-circular cylinders, some specific locations in the circumference are more prone to buckle. The same problem exists for circular cylinders with non-uniform loading in the cross-section like a cylinder under bending. This...conference paper 2010
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Nagy, A.P. (author), Abdalla, M.M. (author), Gürdal, Z. (author)The isogeometric paradigm is aimed at unifying the geometric and analysis descriptions of engineering problems. This unification is brought about by employing the same basis functions describing the geometry to approximate the physical response. Non-uniform rational B-splines (NURBS) are commonly used for this purpose and are adopted in the...journal article 2010
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