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Computational efficiency is always the major concern in aircraft design. The purpose of this paper is to investigate an efficient aeroelasticity optimization design method. Analysis of composite wing elastic axis is presented in the current study and its application on aeroelasticity optimization design is discussed.

Elastic axis consists of stiffness centers. The stiffness centers of eight cross sections are analyzed and the wing elastic axis is obtained through least‐squares procedure. In the analysis of the cross section stiffness center, the wing model is approximated by assuming the wing cross section as a thin walled structure with a single cell closed section and assuming the composite material to be a 3D anisotropic material. In aeroelasticity optimization design, objective functions are taken to be the wing weight and elastic axis position. Design variables are the thickness and area of wing components.

After aeroelasticity optimization design, the wing weight decreases while the divergent velocity increases. Meanwhile, it can achieve an expected result but costs much less computational time than the conventional method.

The results can be used for aircraft design or as an initial value for the next detailed optimization design.

The computational time can be dramatically reduced through the aeroelasticity optimization design based on the elastic axis. It is suitable for engineering applications.

Aircraft wings, one of the most important parts of an aircraft, have seen changes in its topological and design arrangement of both the internal structures and external shape during the past decades. This study, a numerical, aims to minimize the weight of multilaminate composite aerospace structures using multiobjective optimization.

The methodology started with the determination of the requirements, both imposed by the certifying authority and those inherent to the light, aerobatic, simple, economic and robust (LASER) project. After defining the requirements, the loads that the aircraft would be subjected to during its operation were defined from the flight envelope considering finite element analysis. The design vector consists of material choice for each laminate of the structure (20 in total), ply number and lay-up sequence (respecting the manufacturing rules) and main spar position to obtain a lightweight and cheap structure, respecting the restrictions of stress, margins of safety, displacements and buckling.

The results obtained indicated a predominance of the use of carbon fiber. The predominant orientation found on the main spar flange was 0° with its location at 28% of the local chord, in the secondary and main web were ±45°, the skins also had the main orientation at ±45°.

The key innovations in this paper include the evaluation, development and optimization of a laminated composite structure applied to a LASER aircraft wings considering both structural performance and manufacturing costs in multiobjetive optimization. This paper is one of the most advanced investigations performed to composite LASER aircraft.

Describes preliminary structural design work on a notional uninhabited tactical aircraft (UTA), carried out at Cranfield University. UTAs are seen as an important future element of military fleets. A notional baseline requirement was derived, leading to the evolution of a design solution. The basic requirements for such a UTA are naturally highly classified but, although industry has been hesitant to comment, the baseline requirements and design solution developed herein are believed to be reasonable.

To solve the problems of short battery life and low transportation safety of logistics drones, this paper aims to propose a design of logistics unmanned aerial vehicles (UAV) wing with a composite ducted rotor, which combines fixed wing and rotary-wing.

This UAV adopts tiltable ducted rotor combined with fixed wing, which has the characteristics of fast flight speed, large carrying capacity and long endurance. At the same time, it has the hovering and vertical take-off and landing capabilities of the rotary-wing UAV. In addition, aerodynamic simulation analysis of the composite model with a fixed wing and a ducted rotor was carried out, and the aerodynamic influence of the composite model on the UAV was analyzed under different speeds, fixed wing angles of attack and ducted rotor speeds.

The results were as follows: when the speed of the ducted rotor is 2,500 rpm, CL and K both reach maximum values. But when the speed exceeds 3,000 rpm, the lift will decrease; when the angle of attack of the fixed wing is 10° and the rotational speed of the ducted rotor is about 3,000 rpm, the aerodynamic characteristics of the wing are better.

The novelty of this work comes from a composite wing design of a fixed wing combined with a tiltable ducted rotor applied to the logistics UAVs, and the aerodynamic characteristics of the design wing are analyzed.

The purpose of this paper is to present a structural design and optimization module for aircraft structures that can be used stand-alone or in a high-fidelity multidisciplinary design optimization (MDO) process. The module is capable of dealing with different design concepts and novel materials properly. The functionality of the module is also demonstrated.

For fast sizing and optimization, linear static finite element (FE) models are used to obtain inner loads of the structural components. The inner loads and the geometry are passed to a software, where a comprehensive set of analytical failure criteria is applied for the design of the structure. In addition to conventional design processes, the objects of stiffened panels like skin and stringer are not optimized separately and discrete layups can be considered for composites. The module is connected to a design environment, where an automated steering of the overall process and the generation of the FE models is implemented.

The exemplary application on a transport aircraft wing shows the functionality of the developed module.

The weight benefit of not optimizing skin and stringer separately was shown. Furthermore, with the applied approach, a fast investigation of different aircraft configurations is possible without constraining too many design variables as it often occurs in other optimization processes. The flexibility of the module allows numerous investigations on influence of design concepts and failure criteria on the mass and layout of aircraft wings.

The purpose of this paper is to present the concept of the author’s method of fatigue properties assessment of polymer composite structures, especially structures having nodes of concentrated force introduction (NCFI) using fatigue test data of coupons of similar composites and the ratio of their structural stress rate factors.

Basing on fatigue properties of pure composite shells coupons subjected to cyclic loads, and basing on the static strength difference between pure composite shells and shells having the structure affected by NCFI – (considered here as not only a manner of load introduction but also a kind of structural discontinuity), a method of relative fatigue properties reduction (RFPR) was developed. In the RFPR evaluation process, the author used the results of experiments on a special type of an NCFI named “a labyrinth non-adhesive node of concentrated force introduction” (LNA-NCFI) applied in certain composite gliders for fitting glider wings with the fuselage and also referred to design directives relating to primary structure of composite gliders, which are presented in the form of lightness factors linking stress with a structural mass.

The result of RFPR method application matched well with the results of fatigue tests of the LNA-NCFI type of a NCFI. The RFPR method may significantly facilitate the estimation of fatigue life of a structure with a structural discontinuity or an NCFI.

The RFPR method may significantly facilitate the estimation of fatigue life of a structure with a structural discontinuity or an NCFI.

The paper presents a proposal of a novel simplified method for fatigue life estimation of composite structures having a kind of structural discontinuity or an NCFI.

This research outlines the development and characterization of advanced composite materials and their potential applications in the aerospace industry for interior applications. Advanced composites, such as carbon-fiber-reinforced polymers and ceramic matrix composites, offer significant advantages over traditional metallic materials in terms of weight reduction, stiffness and strength. These materials have been used in various aerospace applications, including aircraft, engines and thermal protection systems.

The development of design of experiment–based hybrid aluminum composites using the stir-casting technique has further enhanced the performance and cost-effectiveness of these materials. The design of the experiment was followed to fabricate hybrid composites with nano cerium oxide (nCeO₂) and graphene nanoplatelets (GNPs) as reinforcements in the Al-6061 matrix.

The Al6061 + 3% nCeO2 + 3% GNPs exhibited a high hardness of 119.6 VHN. The ultimate tensile strength and yield strength are 113.666 MPa and 73.08 MPa, respectively. A uniform distribution of reinforcement particulates was achieved with 3 Wt.% of each reinforcement in the matrix material, which is analyzed using scanning electron microscopy. Fractography revealed that brittle and ductile fractures caused the failure of the fractured specimens in the tensile test.

The manufactured aluminum composite can be applied in a range of exterior and interior structural parts like wings, wing boxes, motors, gears, engines, antennas, floor beams, etc. The fan case material of the GEnx engine (currently using carbon-fiber reinforcement plastic) for the Boeing 7E7 can be another replacement with manufactured hybrid aluminum composite, which predicts weight savings per engine of close to 120 kg.

The development of hybrid reinforcements, where two or more types of reinforcements are used in combination, is also a novel approach to improving the properties of these composites. Advanced composite materials are known for their high strength-to-weight ratio. If the newly developed composite material demonstrates superior properties, it can potentially be used to replace traditional materials in aircraft manufacturing. By reducing the weight of aircraft structures, fuel efficiency can be improved, leading to reduced operating costs and environmental impact. This allows for a more customized solution for specific application requirements and can lead to further advancements in materials science and technology.

Currently undergoing NASA flight testing is the Grumman X‐29 forward swept wing (FSW) demonstrator aircraft which was built under a contract sponsored by the Defence Advanced Research Projects Agency (DARPA) and funded through the Air Force. The FSW aircraft first took to the air in December, 1984 and after four flights with the manufacturer was handed over to NASA for a verification programme involving all the benefits of this design. Advanced technology features which will be demonstrated are the forward swept wing for improved aerodynamic efficiency and good control at high angles of attack; tailored composite wing structure that resists the tendency towards structural divergence inherent in this configuration; thin supercritical aerofoil for improved transonic performance at high lift coefficients; variable camber trailing edge to reduce drag at all lift coefficients and avoid supersonic drag associated with aerofoil camber; canard longitudinal control for efficient trimming of variable camber pitching moments and favourable canard‐wing interactions; highly relaxed static stability for very low trim drag at all Mach numbers; and a digital fly‐by‐wire flight control system.

The purpose of this paper was to investigate and evaluate the influence of geometrical and structural design changes in order to reduce shear-lag and increase specific strength and stiffness of thin-walled composite I-beam wing spars.

A detailed FEM model of a cantilevered I-beam spar was used to investigate the influence of increased transition fillet radius and increased web sandwich core thickness on the shear-lag effect at different width to thickness ratios of flanges. Evaluation functions were used to assess specific strength and stiffness of different spar configurations.

Increased web core thickness has greater influence on normal stress distribution and the reduction of the shear-lag than fillet size. Additional weight of thicker core is not compensated enough through reduction of stress concentration. Increased transition fillet and web core thickness increase optimum flanges width to thickness ratio. Shear-lag reduces the strength of the spar more than the stiffness of the spar.

Findings in this study and detailed insight in the shear-lag effect are important for aircraft design when minimum weight of the airframe is of supreme importance.

This combined shear-lag and weight optimization study deals with composite I-beams and loads that are specific for aerospace engineering. This study does not only evaluate the shear-lag phenomena, but primarily analyses fine structural details in order to reduce it, and increases specific strength and stiffness of I-beam spars.