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Das Ziel dieser Arbeit ist es, einen Einblick über die möglichen Methoden zur Überprüfung von statischen Berechnungen zu geben. Anfangs wird die Relevanz des Themas diskutiert und die Notwendigkeit der Überprüfung hinterfragt. Weiters wird ein Einblick in die Grundlagen der statischen Berechnung mit Hilfe der wichtigsten Normenwerke und Richtlinien zur Bemessung und dessen Überprüfung gegeben. Dabei wird unter anderem der Fokus auf die Bemessung mittels EUROCODE gelegt. Weiters werden verschiedene Sicherheitskonzepte und dessen Auswirkung auf die Bemessung behandelt. Ein weiterer Teil der Arbeit beschäftigt sich mit der Notwendigkeit und Problematik der EDV-Statik. Dabei werden anhand von mehreren Aspekten die Vor- und Nachteile der Computer-Statik hervorgehoben. Themen wie Modellbildung und Berechnungsmethoden stehen im Fokus dieses Kapitels. Des Weiteren wird die Optimierung von Bauteilen, sowie der zeitliche Faktor bedingt durch Statik-Programme erörtert.In Kapitel 4 wird auf verschiedene Methoden zur Überprüfung von statischen Berechnungen eingegangen. Die erste Methode ist das sogenannte „Vier-Augen-Prinzip“, bei der die Berechnung durch eine andere Person kontrolliert wird. Die zweite Methode beschreibt den Einsatz von Vorbemessungstabellen und Faustformeln für die Überprüfung des Ergebnisses. Eine weitere Methode beschreibt die Prüfung der Berechnung durch Handrechnungen und die letzte der behandelten Methoden beschreibt den Einsatz einer anderen Software zur Verifizierung des Berechneten. Jede dieser Methoden wird näher betrachtet und deren Vor- und Nachteile werden erläutert. Danach wird anhand von Beispielen der Einsatz der genannten Methoden veranschaulicht, indem anhand einer Angabe eine Berechnung mittels eines Statik-Programmes durchgeführt wird. Das Ergebnis dieser Berechnung wird dann mittels der in Kapitel 4 beschriebenen Methoden überprüft. Im Anschluss daran werden die Methoden in Bezug auf deren Effektivität miteinander verglichen und ein Fazit wird gezogen. The aim of this paper is to give an insight into the possible methods for checking structural calculations. Initially, the relevance of the topic is discussed and the necessity of the verification is questioned. Furthermore, an insight into the basics of structural analysis is given with the help of the most important sets of standards and guidelines for the design and verification of the designs. Among other things, the focus will be on design using EUROCODE. Furthermore, different safety concepts and their effect on the design are shown. Another part of the paper deals with the necessity and problems of computer statics. Thereby, the advantages and disadvantages of computer statics are highlighted on the basis of several aspects. Topics such as modeling and calculation methods are the focus of this chapter. Furthermore, the optimization of components, as well as the time factor caused by statics programs is discussed.Chapter 4 deals with different methods for the verification of structural calculations. The first method is the so-called "four-eyes principle", in which the calculation is checked by another person. The second method describes the use of preliminary design tables and rules of thumb for checking the result. Another method describes checking the calculation by hand calculations and the last of the methods discussed describes the use of other software to verify what has been calculated. Each of these methods is discussed in more detail and advantages and disadvantages are explained. After that, examples are given to illustrate the use of the above methods by performing a calculation using a structural analysis program based on a specification. The result of this calculation is then checked using the methods described in Chapter 4. Subsequently, the methods are compared with each other in terms of their effort effectiveness and a conclusion is drawn. vorgelegt von: Mario Moitzi Abweichender Titel laut Übersetzung der Verfasserin/des Verfassers Bachelorarbeit FH JOANNEUM 2022

Research results are not only presented in research papers, but also in professional papers, monographs, parts of monographs, workshops, seminars which are presented in the bibliography of the entire research programme group.

In this paper, we study the methods for calculating beams with skating in the lower belt of both the Ibeam and box sections. Based on the dependences presented in the existing methods, the stress-strain state of single-beam bridge cranes was calculated at the points of contact of the wheels of the hoist and beam belt, with a box section with rolling along the bottom. Box-section crane cranes have greater rigidity and stability compared to the I-beam section, in addition they allow you to increase the span without sacrificing the crane's lifting capacity. SolidWorks Simulation also performed a finite element analysis of the stress-strain state of boxsection beams with skating along the lower belt. The main advantage of the finite element method is the ability to split into finite elements areas of any shape and, thus, the ability to calculate the stress and strain fields in real details, taking into account all their design features, which ensures high accuracy of the calculation. On the basis of the results obtained, the dependences of stresses on the thickness of the lower girder beam, the position of the hoist wheels were studied, an approximating function was constructed, and a simpler engineering calculation method was proposed that allows one to reduce the number of calculations

The paper deals with the impact of the controlling system adjustment on the level of the dynamic loads operating on the hoisting machine parts during the period of the non-steady motion. The impact of the operating regime of the hoisting machine generalized mechanism on the consistency of operation and the variation of the parameters of the mechanism controlling system with the electric drive and frequency converter is experimentally shown. The procedure of the experiment is described; there are given the comparative results of the variation of the mechanism performance when it works using the controlling system with the frequency converter and brake resistor, and without it, when working on the natural parameters. There are conclusions about adequacy of the normative method for the dynamic coefficient option, determining the loading of the hoisting machine metalware, and in case of occurrence of adjustment errors in the frequency converter controlling system.

The aeroelastic behavior of wing models is nonlinear particularly in the transonic Speed range. The interaction between aerodynamic and structural forces can lead to the occurrence of Limit-Cycle Oscillations (LCOs). If in addition the wing model is flexible and backward swept, the kinematic coupling between bending and torsion makes the Situation even more complex. In the research project ‘‘Aerostabil’’ such a wing was investigated, which was equipped with pressure transducers in three sections and accelerometers. The experiments were performed in the adaptive test section of the transonic wind tunnel TWG in Göttingen. Already Dietz et al. (2003) have reported about experimental details and preliminary results. Based on these data Bendiksen (2008) studied numerically LCO-flutter behavior using a very similar, theoretical model (G-wing) and Stickan et al. (2014) used the original data as a LCO flutter test case. The influence of flexibility on the steady aerodynamics of the wing was described in Schewe & Mai (2018). In this paper now the flutter experiments with the same flexible model were analyzed systematically in the transonic range 0.84

Summary Burst pressure is the pressure at which vessel burst/crack and internal fluid leaks. An accurate prediction of burst pressure is necessary in chemical, medical and aviation industry. Burst pressure is a design safety limit, which should not be exceeded. If this pressure is exceeded it may lead to the mechanical breach and permanent loss of pressure containment. So burst pressure calculation is necessary for all the critical applications. To numerically calculate burst pressure material curve is essential. There are various material models which are used to define material curve, amongst them Ramberg–Osgood is very popular. Ramberg–Osgood accurately capture material curve in strain hardening region. This approach is applicable for different material grades. In this paper a finite element method is used to predict burst pressure using Ramberg–Osgood equation. These results are then compared with results obtained from elasto-plastic curve and true stress strain curve. Results obtained by finite element analysis are validated with experimental data which is considered from open literature.

This paper describes a new analysis method for orthotropic cylindrical shell structures with arbitrary stiffness distribution. The structural model consists of ring frame elements, orthotropic membrane panels and longitudinal stiffeners (stringer). The element stiffness matrix of the orthotropic panel is based on the displacements functions of its boundary only. The boundary value problem is solved by developing the stresses in Taylor series and applying the principal of virtual work (virtual forces). By this way it is possible to have large elements able to describe stress peaks. The method is applied for Booster load introduction into launcher structures and reduces the number of degrees of freedom drastically, allowing rapid analyses necessary for parametric optimization in the pre-design phase.

Morphing is a technology with high potential to reduce emissions in aviation, since it enables wings to adapt their shape to operate at a higher efficiency over the full range of flight conditions. This paper is presenting a concept to adapt camber by drooping the nose. The scope is the setup and bench top testing of a full scale wing tip leading edge wind tunnel model with a morphing droop nose. The complete model features a span of 1.3 m and a strong taper from the root to the tip. For completeness, the design approach is covered as well. The design comprises a GFRP skin to be drooped by two compliant mechanisms, which are driven by linear motors. The compliant morphing devices are “designed-through-optimization”, with the optimization algorithms including Simplex optimization for composite compliant skin design, continuum-based and load path representation topology optimization methods for compliant internal substructure design. The compliant mechanism is manufactured by nickel-titanium alloy to allow high strains in the order of several percent, which is shown to be critical in the design of such compliant mechanisms. In order to validate the models, strains within the mechanisms are measured while drooping the nose in the bench top test. This is done after installing the mechanisms into the leading edge skin. It can be shown, that the simulation for the inboard mechanism is close to the experimental results. The comparison of strain levels in the skin and in the mechanism during droop reveals that the stiffness distribution between these two components is quite different. As a result this ratio can be taken into account in future design processes in order to distribute strains more evenly. Moreover the 3D shapes of the morphed and clean skin are measured and their comparison with the target shapes is presented as well. Finally, the bench top tests are a proof of concept for the overall concept and design which resultes in a “go” for the following low speed subsonic wind tunnel tests.Copyright © 2015 by ASME

A partitioned fluid-structure coupling code for transonic panel flutter has been developed and validated. The Reynolds-averaged Navier-Stokes equations are solved numerically by means of an implicit finite volume method to account for nonlinear aerodynamics, as there are shock waves and a viscous boundary layer at the panel surface. An implicit finite element formulation of the structural equations as well as a Galerkin solution of the von-Karman plate equation are employed to solve elastic panel deformations with respect to geometric nonlinearities. A detailed validation process is presented in this paper for high subsonic and low supersonic Mach numbers. This comprises a discussion of available results from literature with the objective to propose a guideline for validation purposes of partitioned panel flutter solvers. Thereupon the code is used for studies on the impact of turbulent boundary layer characteristics on aeroelastic stability boundaries and post-flutter. An evaluation of flutter modes and frequencies in the post-flutter domain as well as a discussion of the corresponding flow phenomena is presented.

Endwall losses and secondary air flow are considered to be responsible for a significant part of the flow losses in compressors. Their reduction can be achieved by 3D blade design and non-axisymmetric endwalls. In order to evaluate the potential of both effects, an analysis of secondary air flow and the origin of losses is realized. This paper presents multiple numerical simulations to determine the predominant phenomena at the origin of losses in the hub region of the last rotor of the Rig 250, a 4-stage compressor with cantilevered stators and rotor tip clearances. In a first study (I), an inviscid endwall condition at the hub of rotor 4 has been investigated. This condition strongly reduces the secondary air flow from the pressure side to the suction side and shows a significant reduction of the losses in the hub region. But the typical loss distribution over the blade height with a local maximum between 5 and 15 % of the blade height is not changed. Through this study the losses generated by the endwall boundary layer and the resulting secondary air flow are evaluated. Moreover, the potential for endwall contouring and 3D blading in the hub region is estimated, which can be used in future design studies. In the second study (II), ideal radial distributions of the velocity and of the inflow angles at the inlet of the rotor 4 are set. The results show the dependencies between the inflow condition and the loss production in the blade passage near the endwall. These studies sets the theoretical maximal potential for improvement techniques, like endwall contouring or the modification of the upstream stator.

This paper presents the numerical simulations and performance analysis of a 3D scramjet inlet with focus on the effects of sidewall compression and relaminarization. A well-validated �finite volume flow solver was used to simulate a scramjet inlet with a double ramp configuration for outer compression and varying degrees of sidewall compression. The computed wall pressure and heat transfer in the symmetry plane are in close agreement with the measurements and numerical results indicate that sidewall compression alters the inlet performance significantly. The effects of relaminarization over the expansion corner prior to the interior part of the inlet is isolated and studied in both experiment and simulation.

This paper describes the computational analysis of aerodynamic damping for prediction of flutter characteristics of a transonic fan stage that consists of a highly loaded rotor along with a tandem stator. Three dimensional, linearized Navier-Stokes flow solver TRACE is used to numerically analyse the flutter stability of the fan. The linear flow solver enables the modeling of a single blade passage to simulate the desired inter-blade phase angle. The unsteady aerodynamic load on a vibrating blade is obtained by solving the unsteady Navier-Stokes equations on a dynamically deforming grid and the energy exchange method is used to calculate the aerodynamic damping. The calculation of aerodynamic damping for the prediction of flutter characteristics of the fan rotor is carried out with and without considering the influence of the disk. The blade mode shapes from finite element modal analysis are obtained accordingly and the flutter calculations are carried out for three blade vibration modes at the design speed and at part speeds for all possible inter-blade phase angles. Two operating points, one on the working line and the other near stall are investigated at every rotational speed. Different aspects that affect the aerodynamic damping behaviour like part speed operation, variation in unsteady blade surface pressure fluctuation between operating points on the working line and at near stall and the corresponding variation in aerodynamic work, inter-blade phase angle etc., are described. This analysis primarily focuses on the variations in aerodynamic damping of the fan with and without the influence of the disk. In addition, influence and effect of shock wave on the aerodynamic damping is also discussed.

The present paper describes a comprehensive MDO process chain to maximize the range of a transonic transport aircraft configuration. The parameterization incorporates wing plan form parameters and twist angles in four wing sections. The geometrical inputs for the disciplines CFD and CSM were generated by CATIA V5 based on those design parameters which were prescribed by a SUBPLEX optimizer. CFD is at first used to calculate the drag in cruise flight with RANS and secondly to provide aerodynamic forces from Euler solutions from certain maneuver cases for a structural sizing of the wing to yield the wing weight. As with the structural calculations the wing deformations are available, these are used to deform the CFD mesh and to evaluate drag and forces on the corresponding flight shapes. The fluid/structural-sizing procedure, which is performed in every optimization cycle, is repeated several times until a sufficient convergence of drag and wing mass is achieved. Both values are then used to compute the Breguet range, which represents the optimization objective. Finally two optimization runs have been conducted. While the first run lead to a consistent result, in the second run, which includes an additional load case, the best configuration was already found in the fifth cycle.

The use of tail strakes on aft loading transport aircraft is a well proven technique to reduce fuselage upsweep drag. In the present paper the tail flow around a generic aircraft configuration with a swept up tail has been computed using high fidelity CFD analyses. The focus was on the influence and effectiveness of tail strakes and the interaction of the strake with the tail vortices. As it turned out that strakes placed arbitrarily may lead to decrease of aircraft performance, CFD based optimization runs were conducted to find an optimal strake position on the rear fuselage. Finally the optimized configurations were analyzed and the principle of strake tail vortex interaction aiming on a reduction of upsweep drag was clarified.