In a recent investigation conducted by the United States Air Force, the mechanical failure of the aileron lever, manufactured from 2014-T6 aluminum, caused the fatal mishap of a T-38 trainer aircraft. In general the locations of cracks are unknown and must be determined by simulation. In this study we propose to use a continuum damage modeling approach to determine the degradation and damage in a material as the number of cycles of loading increases. This approach successfully predicts the location of crack initiation, propagation path, and propagation rate. A stress-based model in conjunction with the successive initiation technique is utilized. Successive initiation is based on the idea that damage will accrue in a material. Each element inside a new material will have a value of 0 damage assigned to it. Over time, the damage that occurs due to stresses on individual elements will add until the damage reaches a value of 1. At that point, failure of the element will occur. A code was developed in ANSYS that can draw, mesh, and apply appropriate forces on the aileron lever for successive runs. By using the S-N curve for the 2014-T6 aluminum material, the material damage constants are found. This stress-based damage model is then used to determine the state of damage in each element. Each time the elements are stressed, a particular amount of damage will occur. When an element reaches a specific amount of damage, ANSYS will "kill" the element, resulting in the element no longer adding to the stiffness matrix of the material. Variability is a common occurrence in all aspects of engineering such as manufacturing, testing, and loading. A Monte Carlo simulation is used to determine the sensitivity of the results to variability of input parameters by ± 15%. Input parameters include loads, material properties and damage model constants. The Monte Carlo simulation indicates the only significant input in the initiation life of the material is the exponential value in the stress-based fatigue life equation. Material properties and load variations in the ± range will not significantly change the life prediction results.

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A series of wind tunnel tests were conducted to determine the aerodynamic forces and moments produced by several clamped oblique wings. The wing sweep and aileron deflection angles were varied throughout a wide range of dynamic pressures. The wing structure was also stiffened. Strains were measured in the swept forward wing panels. Results from these tests showed that increasing the wing structural stiffness or applying aileron deflection would increase the wing divergence speed. The divergence speed decreased as the sweep angle increased. Further tests were conducted with the wing unconstrained in roll. Results showed that an oblique wing will attempt to unload its sweptforward panel by assuming a banked position. The wings were found to flutter before unclamped divergence occurred. Finally, it was found that the wing loading of an oblique wing can remain constant for a given aileron deflection throughout a wide range of velocities including velocities above the clamped divergence speed. / Master of Science

This diploma thesis targets in concept of wing, aileron, flap and main undercarriage of the ultralight replication of the plane L-40 called Meta Sokol. The thesis developed from cooperation with two other members of the team – Alice Lipková (aerodynamics, power) and Miroslav Růžička (fuselage, tail unit and rear gear). The first part of this diploma thesis is concerned with load and concept of structure of the wing. At first the flight envelope is specified, then charakteristics of shearing force, bending moment and torsion moment are determined spanwise. The concept and subsequent strength verification of structure of the wing is also solved. The same process is claimed to concept of the aileron and the flap. The second part of this diploma thesis is dealt with main landing gear, its support, structure, springing and the principle of retraction. The final passage is devoted to load of the undercarriage.

The objective of this work is to adopt and further expand the type design of the SONG motor glider. The study will result in the basic aerodynamic calculation and the design of lateral control system including structural strength inspection of selected parts. Subsequently, the proposal will allow for further calculation to be made (of flight mechanics, wings strength or fuselage and empennage firmness) and for more specific constructional design of individual components of the glider.

This dissertation consists of three main parts. The first part is to discuss aileron reversal problem for a typical section with linear aerodynamic and structural analysis. The result gives some insight and ideas for this aeroelastic problem. Although the aileron in its post-reversal state will work the opposite of its design, this type of phenomenon as a design root should not be ruled out on these grounds alone, as current active flight-control systems can compensate for this. Moreover, one can get considerably more (negative) lift for positive flap angle in this unusual regime than positive lift for positive flap angle in the more conventional setting. This may have important implications for development of highly maneuverable aircraft. The second part is to involve the nonlinear aerodynamic and structural analyses into the aileron reversal problem. Two models, a uniform cantilevered lifting surface and a rolling aircraft with rectangular wings, are investigated here. Both models have trailing-edge control surfaces attached to the main wings. A configuration that reverses at a relatively low dynamic pressure and flies with the enhanced controls at a higher level of effectiveness is demonstrated. To evaluate how reliable for the data from XFOIL, the data for the wing-aileron system from advanced CFD codes and experiment are used to compare with that from XFOIL. To enhance rolling maneuverability for an aircraft, the third part is to search for the optimal configuration during the post-reversal regime from a design point of view. Aspect ratio, hinge location, airfoil dimension, inner structure of wing section, composite skin, aeroelastic tailoring, and airfoil selection are investigated for cantilevered wing and rolling aircraft models, respectively. Based on these parametric structural designs as well as the aerodynamic characteristics of different airfoils, recommendations are given to expand AAW flight program.

This diploma thesis called „Aileron Design of Composite Materials” deals with the technologies of production used in aricraft industries. It shows appropriate conceptions of composite structures for the airplane aileron of Aero L-159A/B as well as a proposal of an accetable structure for RTM process.

The amphibious fullmetall plane Mermaid is made by company Czech Aircraft Works in Kunovice. Subject of this diploma thesis was involve changes of structure, which pass through during development, to calculation. Within this published work was process: Load calculation of wing Stress analysis of wing Load calculation of aileron Load calculation of flap Load calculation of horizontail tail