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Multidisciplinary Design Optimization Framework for Morphing Wing using Metamaterials
(IEEE, 2025-01-28) Zikmund, Pavel; Kofler, Michael; Navrátil, Jan; Hrstka, Miroslav; Pollák, Jakub; Van Kampen, Erik-Jan
Metamaterials offer innovative potential for morphing wing design. This study investigates two approaches: a variable-stiffness leading edge and a trailing edge with a metamaterial lattice hinge, applying Multidisciplinary Design Optimization to compare these designs against a conventional composite wing. Aerodynamic, structural, and control analyses are integrated, with initial findings bridging 2D aero-structural wing rib design and 3D aerodynamic and control evaluations.
More Haptic Aircraft
(IOP Publishing Ltd, 2024-03-13) Zikmund, Pavel; Horpatzká, Michaela; Procházková, Hana; Macík, Miroslav
This paper presents a comprehensive review of haptic feedback in light aircraft control. It provides an overview of the results and experiences gained from a previous research project focused on the design and testing of pilot haptic feedback hardware. The objective of this paper is to outline a roadmap for the future development of “More Haptic Aircraft,” incorporating principles of human-centred design into light aircraft cockpits equipped with the presented haptic feedback device.
Research of Effects of Defects on Stability Failures of Semi-monocoque Stiffeners
(Vilnius Gediminas Technical University (VGTU) Press, 2020-01-22) Katrňák, Tomáš; Juračka, Jaroslav; Jebáček, Ivo
This article presents further results of the research of effects of model defects on the local buckling of compressed stiffeners in nonlinear finite element (FE) analyses. The main outcomes are confirmation of trends for 10 sets of profile dimensions, final validations of various sets of FE simulations, and designs of practical types of defects with appropriate ratio values. A single node defect and then complex types of defects with alternating distributions of node shifts along one edge, two free flange edges, one flange surface and both flange surfaces are analyzed in this research project. First parts of this paper describe designed FE models with defects, their effects on simulation results, colored graphic visualizations with stress scales and determinations of the sudden failure of stability in the local mode. Then, particular results of FE analyses are validated by a comparison with the results of analytical methods of stability failure. Final detail comparisons of analytical and FE simulation results with data of experimental tests confirm predicted critical buckling forces. The validation of results and design parameters together with the knowledge of effects of model defects on buckling behaviors allows more accurate simulations of internal stiffeners of thin-walled semi-monocoque structures.
Modifications of a simple I-beam and its effects on the stress state
(Taylor & Francis, 2016-12-20) Cejpek, Jakub; Juračka, Jaroslav
The motivation for this work is a desire for a deeper understanding of the structural failures in a composite glider wing, which has been tested in the laboratories of the Institute of Aerospace Engineering, Faculty of Mechanical Engineering, Brno University of Technology. To understand the causes of the encountered failures, one has to consider the effects of all the stages in the design, manufacturing and testing of the wing. This paper focuses only on the design stage. The presented facts were obtained from a finite element analysis. The geometry used for the analysis is that of the tested specimens. This allows validating the results by the comparison of the deformation and strains measured during the laboratory tests. The analysis starts with a simple I-beam loaded by three-point-bending. In the next step a cantilever is added. Several more modifications follow, changing the I-beam to the wing. The case evaluation considers the interaction between normal (material direction 1) and inter-laminar shear stresses in the upper flange. The goal of this paper is to quantify the effect of each design change in the wing structure and loading on the stress plane 1-31.
Timing Is Important: Unmanned Aircraft vs. Satellite Imagery in Plant Invasion Monitoring
(Frontiers Media SA, 2017-05-31) Dvořák, Petr
The rapid spread of invasive plants makes their management increasingly difficult. Remote sensing offers a means of fast and efficient monitoring, but still the optimal methodologies remain to be defined. The seasonal dynamics and spectral characteristics of the target invasive species are important factors, since, at certain time of the vegetation season (e.g., at flowering or senescing), plants are often more distinct (or more visible beneath the canopy). Our aim was to establish fast, repeatable and a cost-efficient, computer-assisted method applicable over larger areas, to reduce the costs of extensive field campaigns. To achieve this goal, we examined how the timing of monitoring affects the detection of noxious plant invaders in Central Europe, using two model herbaceous species with markedly different phenological, structural, and spectral characteristics. They are giant hogweed (Heracleum mantegazzianum), a species with very distinct flowering phase, and the less distinct knotweeds (Fallopia japonica, F. sachalinensis, and their hybrid F. × bohemica). The variety of data generated, such as imagery from purposely-designed, unmanned aircraft vehicle (UAV), and VHR satellite, and aerial color orthophotos enabled us to assess the effects of spectral, spatial, and temporal resolution (i.e., the target species' phenological state) for successful recognition. The demands for both spatial and spectral resolution depended largely on the target plant species. In the case that a species was sampled at the most distinct phenological phase, high accuracy was achieved even with lower spectral resolution of our low-cost UAV. This demonstrates that proper timing can to some extent compensate for the lower spectral resolution. The results of our study could serve as a basis for identifying priorities for management, targeted at localities with the greatest risk of invasive species' spread and, once eradicated, to monitor over time any return. The best mapping strategy should reflect morphological and structural features of the target plant and choose appropriate spatial, spectral, and temporal resolution. The UAV enables flexible data acquisition for required time periods at low cost and is, therefore, well-suited for targeted monitoring; while satellite imagery provides the best solution for larger areas. Nonetheless, users must be aware of their limits.

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