The first part of the diploma thesis with name „Hybrid adhesive bonded joints of metals and composite materials“ comprise surface pretreatment review. There is also mentioned current review of adhesives for composite and aluminium adherends. The second part of the thesis is dedicated to lap hybrid joint shear strength tests. The effects of adherend thickness, overlap lenght and surface pretreatment on shear strength were investigated. Measured parameters of hybrid joints are proved with a FE analysis with enough accuracy. Conclusions could be used for optimum design of hybrid joint with aluminium and composite adherends.

<p>Naturally-occurring biological materials with stiff mineralized reinforcement embedded in a ductile matrix are commonly known to achieve excellent balance between stiffness, strength and ductility. Interestingly, nature offers a broad diversity of architectural motifs, exemplify the multitude of ways in which exceptional mechanical properties can be achieved. Such diversity is the source of bio-inspiration and its translation to synthetic material systems. In particular, the helicoid and the “brick and mortar” architectured materials are two key architectural motifs we are going to study and to synthesize new bio-inspired materials. </p> <p>Due to geometry mismatch(misorientation) and incompatibilities of mechanical properties between fiber and matrix materials, it is acknowledged that misoriented stiff fibers would rotate in compliant matrix beneath uniaxial deformation. However, the role of fiber reorientation inside the flexible matrix of helicoid composites on their mechanical behaviors have not yet been extensively investigated. In the present project, fiber reorientation values of single misoriented laminae, mono-balanced laminates and helicoid architectures under uniaxial tensile are calculated and compared. In the present work, we introduce a Discontinuous Fiber Helicoid (DFH) composite inspired by both the helicoid microstructure in the cuticle of mantis shrimp and the nacreous architecture of the red abalone shell. We employ 3D printed specimens, analytical models and finite element models to analyze and quantify in-plane fiber reorientation in helicoid architectures with different geometrical features. We also introduce additional architectures, i.e., single unidirectional lamina and mono-balanced architectures, for comparison purposes. Compared with associated mono-balanced architectures, helicoid architectures exhibit less fiber reorientation values and lower values of strain stiffening. The explanation for this difference is addressed in terms of the measured in-plane deformation, due to uniaxial tensile of the laminae, correlated to lamina misorientation with respect to the loading direction and lay-up sequence.</p> <p>In addition to fiber, rod-like, reinforced laminate, platelet reinforced composite materials, “brick and mortar” architectures, are going to be discussed as well, since it can provide in-plane isotropic behavior on elastic modulus that helicoid architecture can offer as well, but with different geometries of reinforcement. Previous “brick and mortar” models available in the literature have provided insightful information on how these structures promote certain mechanisms that lead to significant improvement in toughness without sacrificing strength. In this work, we present a detailed comparative analysis that looks at the three-dimensional geometries of the platelet-like and rod-like structures. However, most of these previous analyses have been focused on two-dimensional representations. We 3D print and test rod-like and tablet-like architectures and analyze the results employing a computational and analytical micromechanical model under a dimensional analysis framework. In particular, we focus on the stiffness, strength and toughness of the resulting structures. It is revealed that besides volume fraction and aspect ratio of reinforcement, the effective shear and tension area in the matrix governs the mechanical behavior as well. In turns, this leads to the conclusion that rod-like microstructures exhibit better performance than tablet-like microstructures when the architecture is subjected to uniaxial load. However, rod-like microstructures tend to be much weaker and brittle in the transverse direction. On the other hand, tablet-like architectures tend to be a much better choice for situations where biaxial load is expected.</p> <p>Through varying the geometry of reinforcement and changing the orientation of reinforcement, different architectural motifs can promote in-plane mechanical properties, such as strain stiffening under uniaxial tensile, strength and toughness under biaxial tensile loading. On the other hand, the various out-of-plane orientation of the reinforcement leads to functionally graded effective indentation stiffness. The external layer of nacre shell is composed of calcite prisms with graded orientation from surface to interior. This orientation gradient leads to functionally graded Young’s modulus, which is confirmed to have higher fracture resistance than homogenous materials under mode I fracture loading act.</p> <p>Similar as graded prism orientation in calcite layer of nacre, the helicoid architecture found in nature exhibits gradients on geometrical parameters as well. The pitch distance of helicoid architecture is found to be functionally graded through the thickness of biological materials, including the dactyl club of mantis shrimp and the fish scale of coelacanth. This can be partially explained by the long-term evolution and selection of living organisms to create high performance biological materials from limited physical, chemical and geometrical elements. This naturally “design” procedure can provide us a spectrum of design motifs on architectural materials. </p> <p>In the present work, linear gradient on pitch distance of helicoid architectures, denoted by functionally graded helicoid (FGH), is chose to be the initial pathway to understand the functionality of graded pitch distance, associated with changing pitch angle. Three-point bending on short beam and low-velocity impact tests are employed in FEA to analyze the mechanical properties of composite materials simultaneously. Both static(three-point bending) and dynamic(low-velocity impact) tests reveal that FGH with pitch angle increasing from surface to interior can provide multiple superior properties at the same time, such as peak load and toughness, while the helicoid architectures with constant pitch angle can only provide one competitive property at one time. Specifically, helicoid architectures with smaller pitch angle, such as 15-degree, show higher values on toughness, but less competitive peak load under static three-point bending loading condition, while helicoid architectures with middle pitch angle, larger than or equal to 22.5-degree and smaller than 45-degree, exhibit less value of toughness, but higher peak load. The explanation on this trend and the benefits of FGH is addressed by analyzing the transverse shear stresses distribution through the thickness in FEA, combined with analytical prediction. In low-velocity impact tests, the projected delamination area of helicoid architectures is observed to increase when the pitch angle is decreasing. Besides, laminates with specific pitch angles, such as 45-degree, classical quasi-isotropic laminate, 60-degree, specific angle ply, and 90-degree, cross-ply, are designed to compare with helicoid architectures and FGH.</p>

In the automobile industry, there is a big push for the automotive car manufacturers to base engineering decisions on the results of Computer Aided Engineering (CAE) solutions, and to transform the prototyping and testing, from a costly iterative process to a final verification and validation step. The variability in components material properties and environmental conditions together with the lack of knowledge about the underlying physics of complex systems often make it impractical to make reliable predictions based on only deterministic CAE models. One such area is the CAE modelling of cast aluminium components. These cast aluminium components have gained a huge relevance in the automobile industries due to their commendable mechanical properties. The advantage of the cast aluminium alloys are being a well-established alloy system in manufacturing processes, their functional integrity and relatively low weight. However, the presence of pores and micro-voids obtained during the manufacturing process constitutes a specific material behaviour and establishes a challenge in modelling of the cast materials. Furthermore, the low ductility of the materialdemands for the advanced numerical model to predict the failure. The main focus of this master thesis work is to investigate modelling technique of a cast aluminium alloy component, a spring tower, for a drop tower test and validate the predicted behaviour with the physical test results. Volvo Car Corporation currently uses a material model provided by MATFEM for cast aluminium parts which are explored in this thesis work, to validate the material model for component level testing. The methodology used to achieve this objective was to develop a boundary condition to perform component level tests in the drop tower and to correlate these with the obtained results found by using various modelling techniques in the explicit solver LS-DYNA. Therefore, precise and realistic modelling of the drop tower is crucial because the simulation results can be influenced by major design changes. A detailed finite element model for the spring tower has been developed from the observations made during the physical testing. The refined model showed good agreement with the existing model for the spring tower and observations from physical tests.

Die Analyse des Standes der Technik zu Simulationsmethoden im Werkzeugentwicklungsprozess zeigt die breiten Bestrebungen ganzheitliche Modelle zur Abbildung der Maschinen- und Werkzeugeigenschaften in der Prozesssimulation zu schaffen um die Werkzeuginbetriebnahme in Zukunft in die virtuelle Welt überführen zu können. Dabei werden die Einflüsse wie die Stößelkippung unter Last, die Durchbiegung der Werkzeugaufspannplatten, die Verformung des Ziehkissens und die elastische Nachgiebigkeit der Werkzeuge separat betrachtet. Es konnte kein Simulationsmodell identifiziert werden, welche alle relevanten Eigenschaften der Werkzeuge und der Maschinen zu einem Gesamtmodell vereint. Zudem fehlten Modellierungsansätze für wesentliche Teilaspekte einer ganzheitlichen Abbildung der Wechselwirkungen von Maschine, Werkzeug und Prozess. Insbesondere ist dabei die systematische Untersuchung zur Abbildung des Pinolentragbildes sowohl örtlich als auch über dem Pressenhub und der versteifende Einfluss der Werkzeugführung zu nennen. Mit der vorliegenden Arbeit konnte ein ganzheitliches FE-Prozessmodell mit den wesentlichen elastischen Eigenschaften der Maschine und der Werkzeuge erstellt werden. Wichtig ist dabei insbesondere die systematische Abbildung relevanter mechanischer Ziehkissenstrukturen als Ersatzmodell und die Integration der tatsächlichen Ziehkissenkraft im Prozessmodell. Bekannte Modellierungsansätze wie z.B. die Abbildung der Kippsteifigkeit des Stößelsystems und die Berücksichtigung der Durchbiegung der Werkzeugaufspannplatten wurden weiterentwickelt und in das Gesamtmodell implementiert. Für jedes Ersatzmodell wurde eine Strategie zur Modellerstellung und zur zweckmäßigen Parametrierung mit dem Ziel eines minimalen Zeit- und Kostenaufwandes vorgeschlagen. Die elastische Modellierung der Werkzeuge wurde mit einer systematischen Vorgehensweise hinterlegt und zeigt bei konsequenter Anwendung signifikant reduzierte Berechnungszeiten. Die Berücksichtigung der Ziehstäbe erfolgt in dieser Arbeit aufgrund der Einschränkungen des verwendeten FE-Solvers als Strukturmodell. Zusätzlich wurde ein Modellierungsansatz vorgestellt, welcher die analytische Berücksichtigung der Ziehstäbe auf elastischen Werkzeugstrukturen ermöglicht. Damit steht jetzt ein Prozessmodell mit den relevanten Maschinen- und Werkzeugeigenschaften zur Verfügung, welches durch eine einfache Parametrierung auf die jeweilige Prozess-Maschinen-Konfiguration angepasst werden kann. Dies ermöglicht eine deutlich genauere Abbildung des Pinolentragbildes, der daraus resultierenden Niederhalterdruckverteilung und damit des Materialeinzuges in die Matrize. Dieses erweiterte Prozessmodell ist damit in der Lage eine virtuelle Inbetriebnahme der Werkzeuge zu unterstützen und in Zukunft eine weitere Verkürzung des Inbetriebnahmeprozesses zu ermöglichen.:I. Inhaltsverzeichnis I II. Formelzeichen und Abkürzungen V II.1. Formelzeichen V II.2. Abkürzungen VI 1 Einführung 2 2 Stand der Technik 4 2.1 Modellierung des Blechwerkstoffes 6 2.1.1 Strukturelle und funktionale Abbildung 6 2.1.2 Ermittlung der Parameterwerte 9 2.2 Reibungsverhältnisse in der Kontaktfuge 10 2.2.1 Strukturelle und funktionale Abbildung 11 2.2.2 Ermittlung der Parameterwerte 11 2.3 Karosserieziehwerkzeuge 12 2.3.1 Prinzip und Bedeutung für den Umformprozess 12 2.3.2 Wechselwirkungen im Gesamtsystem Presse-Werkzeug-Prozess 15 2.3.3 Strukturelle und funktionale Abbildung in der FE-Prozesssimulation 16 2.3.4 Ermittlung der Parameterwerte 18 2.4 Pressen der Blechumformung 18 2.4.1 Prinzip und Bedeutung für den Umformprozess 18 2.4.2 Wechselwirkungen im Gesamtsystem Presse-Werkzeug-Prozess 22 2.4.3 Strukturelle und funktionale Abbildung der Maschine in der Prozesssimulation 26 2.4.4 Ermittlung von Pressenparameter 30 2.5 Werkzeugentwicklung und -inbetriebnahme 33 2.5.1 Werkzeuginbetriebnahme 34 2.5.2 Simulationsmethoden zur Unterstützung der Werkzeugeinarbeitung 35 2.6 Defizite in der FE-Prozesssimulation des Karosserieziehprozesses 36 3 Zielstellung, Abgrenzung und Vorgehensweise 38 4 Modellerweiterung Werkzeug 40 4.1 Simulationsumgebung 40 4.2 Virtuelles Testwerkzeug 40 4.3 Elastische Werkzeugstruktur 43 4.4 Werkzeuganbindung an umliegende Strukturen 48 4.4.1 Matrize und Stempel 48 4.4.2 Niederhalter 48 4.4.3 Abbildung der Ziehstäbe auf elastisch modellierten Werkzeugen 50 4.5 Die Werkzeugführung 54 4.5.1 Analytische Berechnung der Wirkung der Werkzeugführung 54 4.5.2 Messtechnische Berücksichtigung 56 4.5.3 Bewertung der Modellierungsansätze 56 4.6 Zwischenfazit zur Modellerweiterung der Werkzeuge 58 5 Modellerweiterung Maschine 60 5.1 Messung der Stößel- und Tischdurchbiegung 60 5.2 Ersatzmodellierung und Parametrierung 61 5.3 Überlagerung von Stößelkippung und -durchbiegung 64 5.4 Berücksichtigung der Tischdurchbiegung 67 5.5 Modellstrukturen zur Berücksichtigung der ZK-Mechanik 67 5.6 Kippelastischer Modellierungsansatz 70 5.6.1 1-Punktziehkissen mit Führung 70 5.6.2 2- und 4-Punktziehkissen 72 5.6.3 Ziehkissen mit mehr als 4 Druckpunkten 73 5.7 Elastische Abbildung des Druckkastens 74 5.7.1 Strukturmodell des Druckkastens 74 5.7.2 Ersatzmodell des Druckkastens 76 5.8 Modellstrukturen zur Berücksichtigung der Krafterzeugung 78 5.8.1 Ziehkissenkraft als wegabhängige Größe 79 5.8.2 Ziehkissen-Istkraft als Verhaltensmodell 80 5.8.3 Integration eines reduzierten Anlagenmodells 80 5.9 Ableitung einer Standardparametrierung 84 5.10 Zwischenfazit zu Modellerweiterungen Presse 85 6 Anwendung der Modellerweiterungen auf Versuchsumgebung 88 6.1 Versuchsumgebung 88 6.1.1 Versuchsmaschine 88 6.1.2 Blechwerkstoffe 89 6.1.3 Versuchswerkzeug 91 6.1.4 Messwerterfassung 92 6.2 Modellierung des Blechwerkstoffes 95 6.3 Reibungsverhältnis zwischen Blech und Werkzeug 96 6.4 Modellerweiterungen Werkzeug 98 6.4.1 Modellerstellung 98 6.4.2 Einflussanalyse der elastischen Werkzeugeigenschaften 99 6.5 Modellerweiterung Maschine 100 6.5.1 Berücksichtigung der elastischen Eigenschaften des Stößelsystems 100 6.5.2 Berücksichtigung der Ziehkissenmechanik 105 6.5.3 Validierung der erweiterten FE-Prozessmodelle 109 6.6 Modellbewertung anhand Grenzformänderungsdiagramme 112 6.7 Modellierung der Regelabweichungen der Ziehkissenzylinderkräfte 113 6.8 Anwendung der Standardparametrierung 116 7 Anwendungsbeispiele für die Werkzeugentwicklung 118 7.1 Werkzeugkonstruktion am Beispiel der Fertigungstoleranzen 118 7.2 Werkzeuginbetriebnahme 120 7.2.1 Ermittlung der Zylindersollkräfte auf Mehrpunktziehkissen 121 7.2.2 Virtuelles Tuschieren der Werkzeughälften 123 8 Zusammenfassung 126 9 Literatur 128 III. Anhang 136

In this thesis, the authors investigate how machine learning can be utilized for speeding up the design optimization process of gas turbines. The Finite Element Analysis (FEA) steps of the design process are examined if they can be replaced with machine learning algorithms. The study is done using a component with given constraints that are provided by Siemens Energy AB. With this component, two approaches to using machine learning are tested. One utilizes design parameters, i.e. raw floating-point numbers, such as the height and width. The other technique uses a high dimensional mesh as input. It is concluded that using design parameters with surrogate models is a viable way of performing design optimization while mesh input is currently not. Results from using different amount of data samples are presented and evaluated.

This thesis report aims to help the client developing their new product. The new product to be developed is a safety bracket for a safety system. The safety bracket connects different parts which create the safety system and it should be able to withstand impacts from moving objects. The client has a set of requirements that needs to be addressed during the product development process. One of the most important requirements that must be fulfilled is the given impact energy that the safety bracket must withstand. The methodology used during this thesis work is the product development processes (PDP). The product development process is used to find concepts that have the potential to answer the research questions and to fulfil the requirements. Some methods used in the product development process are brainstorming, brainwriting and combining working principles. The concepts were evaluated with a combination of Pugh´s matrix and weighting matrix. The three best concepts were selected for further development and tested with FEA simulation with Abaqus CAE. The impact simulation gave indications if the concepts could handle the impact energy and if they could fulfil the requirements. All three concepts could withstand the impact energy based on the simulations and most of the requirements could be fulfilled. The concepts with thinner profile walls had a reduction in stress and an increase in impact duration, where the kinetic energy is distributed throughout the impact. A protective shell helps with the reduction of stress and the energy absorption during the impact simulation.

The thesis presents deals with the design, analysis, test and control of permanent magnetsynchronous motor(PMSM). An analytical model was carried out based on the d-q frame and the equivalent circuit of PMSM, theanalytical model gives an approximation value of the machine parameters and is carried out byequations from the listed references. this phase includes many iteration steps, once the results wereobtained they were compared with the motor specifications and if they don’t match the requiredspecifications the process must be done again until the desired design is obtained. Once the analytical model is obtained a Finite Element Simulation was carried out using FEMMsoftware to validate the design, in this phase the designed machine in the analytical model isanalyzed and validated, once the simulation is done the results from both models are compared anddiscussed in the results chapter. It’s important to mark that during the design phase some design parameters were affected andlimited by some factors, for example, the air gap length has been magnified due to manufacturinglimits. The manufacturing process and the prototype building have been started once the optimal designwas selected, the manufacturing process was explained and a comparison study was made to selectthe best manufacturing process suitable and available for this thesis.

In dieser Arbeit wurde ein Arbeitsablauf entwickelt, um ein möglichst realistisches, biomechanisches Modell eines menschlichen Schädelknochens anhand eines Patienten-CT Datensatzes zu erstellen. Mit diesem Modell konnten Experimente aus der Literatur realistisch nachgestellt und anschließend der Mechanismus einer Orbitawandfraktur genauer untersucht werden. Es konnte gezeigt werden, dass das entwickelte Schädelmodell als Alternative für experimentelle biomechanische Untersuchungen verwendet werden kann. Somit sind eine Vielzahl parametrischer biomechanischer Studien möglich, ohne dabei auf Humanpräparate angewiesen zu sein.

Introduction: As fractures of the supraorbital region are far less common than midfacial or orbital fractures, a study was initiated to investigate whether fist blows could lead to fractures similar to those often seen in the midface. Methods: A detailed skull model and an impactor resembling a fist were created and a fist blow to the supraorbital region was simulated. A transient finite element analysis was carried out to calculate von Mises stresses, peak force, and impact time. Results: Within the contact zone of skull and impactor critical stress values could be seen which lay at the lower yield border for potential fractures. A second much lower stress zone was depicted in the anterior-medial orbital roof. Conclusions: In this simulation a fist punch, which could generate distinct fractures in the midface and naso-ethmoid-orbital region, would only reach the limits of a small fracture in the supraorbital region. The reason is seen in the strong bony architecture. Much higher forces are needed to create severe trauma in the upper face which is supported by clinical findings. Finite element analysis is the method of choice to investigate the impact of trauma on the human skeleton.:Background; Methods; Rersults; Discussion; Results; Consent

In der fleischverarbeitenden Industrie gibt es eine Vielzahl von Schneidwerkzeugen. Kuttermesser stehen hierbei in der Prozesskette weit hinten und haben einen direkten Einfluss auf die Qualität des Endprodukts. Der Prozess des Kutterns ist bislang nicht komplett analytisch geklärt. Während des Vorgangs durchläuft das Schneidgut (i.A. das Fleisch bzw. das Brät) wechselnde Aggregatzustände von fester (leicht gefrorener) Form hin zum zähviskosen Zustand. Weiterhin ist es permanentem korrosiven Kontakt ausgesetzt. Die Komplexität macht eine analytische Herangehensweise äußerst aufwendig, sodass sich mittels der FEM durch numerisches Vorgehen und Lastannahmen aus Untersuchungen diesem Problem gewidmet wird. Dabei sind bislang nicht bekannte Potentiale zu erkennen. Hierbei wurden verschiedene Vernetzungsstrategien (p- und h-Methode) der FEM angewandt und verglichen. Es sind dabei Materialreduktionen bis knapp 30% ersichtlich.