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With the burgeoning computing power available, multiscale modelling and simulation has these days become increasingly capable of capturing the details of physical processes on different scales. The mechanical behavior of solids is oftentimes the result of interaction between multiple spatial and temporal scales at different levels and hence it is a typical phenomena of interest exhibiting multiscale characteristic. At the most basic level, properties of solids can be attributed to atomic interactions and crystal structure that can be described on nano scale. Mechanical properties at the macro scale are modeled using continuum mechanics for which we mention stresses and strains. Continuum models, however they offer an efficient way of studying material properties they are not accurate enough and lack microstructural information behind the microscopic mechanics that cause the material to behave in a way it does. Atomistic models are concerned with phenomenon at the level of lattice thereby allowing investigation of detailed crystalline and defect structures, and yet the length scales of interest are inevitably far beyond the reach of full atomistic computation and is rohibitively expensive. This makes it necessary the need for multiscale models. The bottom line and a possible avenue to this end is, coupling different length scales, the continuum and the atomistics in accordance with standard procedures. This is done by recourse to the Cauchy-Born rule and in so doing, we aim at a model that is efficient and reasonably accurate in mimicking physical behaviors observed in nature or laboratory. In this work, we focus on concurrent coupling based on energetic formulations that links the continuum to atomistics. At the atomic scale, we describe deformation of the solid by the displaced positions of atoms that make up the solid and at the continuum level deformation of the solid is described by the displacement field that minimize the total energy. In the coupled model, continuum-atomistic, a continuum formulation is retained as the overall framework of the problem and the atomistic feature is introduced by way of constitutive description, with the Cauchy-Born rule establishing the point of contact. The entire formulation is made in the framework of nonlinear elasticity and all the simulations are carried out within the confines of quasistatic settings. The model gives direct account to measurable features of microstructures developed by crystals through sequential lamination.

In this work the investigation of a (Ti, Al, Si) N system was done. The main point of investigation was to study the possibility of getting the nanocomposite coatings structures by deposition of multilayer films from TiN, AlSiN, . This tries to understand the relation between the mechanical properties (hardness, Young s modulus), and the microstructure (nanocrystalline with individual phases). Particularly special attention was given to the temperature effects on microstructural changes in annealing at 600 °C for the coatings. The surface hardness, elastic modulus, and the multilayers diffusion and compositions were the test tools for the comparison between the different coated samples with and without annealing at 600 °C. To achieve this object a rectangular aluminum vacuum chamber with three unbalanced sputtering magnetrons for the deposition of thin film coatings from different materials was constructed The chamber consists mainly of two chambers, the pre-vacuum chamber to load the workpiece, and the main vacuum chamber where the sputtering deposition of the thin film coatings take place. The workpiece is moving on a car travel on a railway between the two chambers to the position of the magnetrons by step motors. The chambers are divided by a self constructed rectangular gate controlled manually from outside the chamber. The chamber was sealed for vacuum use using glue and screws. Therefore, different types of glue were tested not only for its ability to develop an uniform thin layer in the gap between the aluminum plates to seal the chamber for vacuum use, but also low outgassing rates which made it suitable for vacuum use. A epoxy was able to fulfill this tasks. The evacuation characteristics of the constructed chamber was improved by minimizing the inner surface outgassing rate. Therefore, the throughput outgassing rate test method was used in the comparisons between the selected two aluminum materials (A2017 and A5353) samples short time period (one hour) outgassing rates. Different machining methods and treatments for the inner surface of the vacuum chamber were tested. The machining of the surface of material A (A2017) with ethanol as coolant fluid was able to reduce its outgassing rate a factor of 6 compared with a non-machined sample surface of the same material. The reduction of the surface porous oxide layer on the top of the aluminum surface by the pickling process with HNO3 acid, and the protection of it by producing another passive non-porous oxides layer using anodizing process will protect the surface for longer time and will minimize the outgassing rates even under humid atmosphere The residual gas analyzer (RGA) 6. Summary test shows that more than 85% of the gases inside the test chamber were water vapour (H2O) and the rests are (N2, H2, CO), so liquid nitrogen water vapor trap can enhance the chamber pumping down process. As a result it was possible to construct a chamber that can be pumped down using a turbo molecular pump (450 L/s) to the range of 1x10-6 mbar within one hour of evacuations where the chamber volume is 160 Litters and the inner surface area is 1.6 m2. This is a good base pressure for the process of sputtering deposition of hard thin film coatings. Multilayer thin film coating was deposited to demonstrate that nanostructured thin film within the (Ti, Al, Si) N system could be prepared by reactive magnetron sputtering of multi thin film layers of TiN, AlSiN. The (SNMS) spectrometry of the test samples show that a complete diffusion between the different deposited thin film coating layers in each sample takes place, even at low substrate deposition temperature. The high magnetic flux of the unbalanced magnetrons and the high sputtering power were able to produce a high ion-toatom flux, which give high mobility to the coated atoms. The interactions between the high mobility of the coated atoms and the ion-to-atom flux were sufficient to enhance the diffusion between the different deposited thin layers. It was shown from the XRD patterns for this system that the structure of the formed mixture consists of two phases. One phase is noted as TiN bulk and another detected unknown amorphous phase, which can be SiNx or AlN or a combination of Ti-Al-Si-N. As a result we where able to deposit a nanocomposite coatings by the deposition of multilayers from TiN, AlSiN thin film coatings using the constructed vacuum chamber

Hydrogels are known to be covalently or ionic cross-linked, hydrophilic three-dimensional
polymer networks, which exist in our bodies in a biological gel form such as the vitreous
humour that fills the interior of the eyes. Poly(N-isopropylacrylamide) (poly(NIPAAm))
hydrogels are attracting more interest in biomedical applications because, besides others, they
exhibit a well-defined lower critical solution temperature (LCST) in water, around 31–34°C,
which is close to the body temperature. This is considered to be of great interest in drug
delivery, cell encapsulation, and tissue engineering applications. In this work, the
poly(NIPAAm) hydrogel is synthesized by free radical polymerization. Hydrogel properties
and the dimensional changes accompanied with the volume phase transition of the
thermosensitive poly(NIPAAm) hydrogel were investigated in terms of Raman spectra,
swelling ratio, and hydration. The thermal swelling/deswelling changes that occur at different
equilibrium temperatures and different solutions (phenol, ethanol, propanol, and sodium
chloride) based on Raman spectrum were investigated. In addition, Raman spectroscopy has
been employed to evaluate the diffusion aspects of bovine serum albumin (BSA) and phenol
through the poly(NIPAAm) network. The determination of the mutual diffusion coefficient,
\(D_{mut}\) for hydrogels/solvent system was achieved successfully using Raman spectroscopy at
different solute concentrations. Moreover, the mechanical properties of the hydrogel, which
were investigated by uniaxial compression tests, were used to characterize the hydrogel and to
determine the collective diffusion coefficient through the hydrogel. The solute release coupled
with shrinking of the hydrogel particles was modelled with a bi-dimensional diffusion model
with moving boundary conditions. The influence of the variable diffusion coefficient is
observed and leads to a better description of the kinetic curve in the case of important
deformation around the LCST. A good accordance between experimental and calculated data
was obtained.

This research explores the development of web based reference software for
characterisation of surface roughness for two-dimensional surface data. The reference software used for verification of surface characteristics makes the evaluation methods easier for clients. The algorithms used in this software
are based on International ISO standards. Most software used in industrial measuring
instruments may give variations in the parameters calculated due to numerical changes in
calculation. Such variations can be verified using the proposed reference software.
The evaluation of surface roughness is carried out in four major steps: data capture, data
align, data filtering and parameter calculation. This work walks through each of these steps
explaining how surface profiles are evaluated by pre-processing steps called fitting and
filtering. The analysis process is then followed by parameter evaluation according to DIN EN
ISO 4287 and DIN EN ISO 13565-2 standards to extract important information from the
profile to characterise surface roughness.

The growing computational power enables the establishment of the Population Balance Equation (PBE)
to model the steady state and dynamic behavior of multiphase flow unit operations. Accordingly, the twophase
flow
behavior inside liquid-liquid extraction equipment is characterized by different factors. These
factors include: interactions among droplets (breakage and coalescence), different time scales due to the
size distribution of the dispersed phase, and micro time scales of the interphase diffusional mass transfer
process. As a result of this, the general PBE has no well known analytical solution and therefore robust
numerical solution methods with low computational cost are highly admired.
In this work, the Sectional Quadrature Method of Moments (SQMOM) (Attarakih, M. M., Drumm, C.,
Bart, H.-J. (2009). Solution of the population balance equation using the Sectional Quadrature Method of
Moments (SQMOM). Chem. Eng. Sci. 64, 742-752) is extended to take into account the continuous flow
systems in spatial domain. In this regard, the SQMOM is extended to solve the spatially distributed
nonhomogeneous bivariate PBE to model the hydrodynamics and physical/reactive mass transfer
behavior of liquid-liquid extraction equipment. Based on the extended SQMOM, two different steady
state and dynamic simulation algorithms for hydrodynamics and mass transfer behavior of liquid-liquid
extraction equipment are developed and efficiently implemented. At the steady state modeling level, a
Spatially-Mixed SQMOM (SM-SQMOM) algorithm is developed and successfully implemented in a onedimensional
physical spatial domain. The integral spatial numerical flux is closed using the mean mass
droplet diameter based on the One Primary and One Secondary Particle Method (OPOSPM which is the
simplest case of the SQMOM). On the other hand the hydrodynamics integral source terms are closed
using the analytical Two-Equal Weight Quadrature (TEqWQ). To avoid the numerical solution of the
droplet rise velocity, an analytical solution based on the algebraic velocity model is derived for the
particular case of unit velocity exponent appearing in the droplet swarm model. In addition to this, the
source term due to mass transport is closed using OPOSPM. The resulting system of ordinary differential
equations with respect to space is solved using the MATLAB adaptive Runge–Kutta method (ODE45). At
the dynamic modeling level, the SQMOM is extended to a one-dimensional physical spatial domain and
resolved using the finite volume method. To close the mathematical model, the required quadrature nodes
and weights are calculated using the analytical solution based on the Two Unequal Weights Quadrature
(TUEWQ) formula. By applying the finite volume method to the spatial domain, a semi-discreet ordinary
differential equation system is obtained and solved. Both steady state and dynamic algorithms are
extensively validated at analytical, numerical, and experimental levels. At the numerical level, the
predictions of both algorithms are validated using the extended fixed pivot technique as implemented in
PPBLab software (Attarakih, M., Alzyod, S., Abu-Khader, M., Bart, H.-J. (2012). PPBLAB: A new
multivariate population balance environment for particulate system modeling and simulation. Procedia
Eng. 42, pp. 144-562). At the experimental validation level, the extended SQMOM is successfully used
to model the steady state hydrodynamics and physical and reactive mass transfer behavior of agitated
liquid-liquid extraction columns under different operating conditions. In this regard, both models are
found efficient and able to follow liquid extraction column behavior during column scale-up, where three
column diameters were investigated (DN32, DN80, and DN150). To shed more light on the local
interactions among the contacted phases, a reduced coupled PBE and CFD framework is used to model
the hydrodynamic behavior of pulsed sieve plate columns. In this regard, OPOSPM is utilized and
implemented in FLUENT 18.2 commercial software as a special case of the SQMOM. The dropletdroplet
interactions
(breakage
and
coalescence)
are
taken
into
account
using
OPOSPM,
while
the
required
information
about
the
velocity
field
and
energy
dissipation
is
calculated
by
the
CFD
model.
In
addition
to
this,
the proposed coupled OPOSPM-CFD framework is extended to include the mass transfer. The
proposed framework is numerically tested and the results are compared with the published experimental
data. The required breakage and coalescence parameters to perform the 2D-CFD simulation are estimated
using PPBLab software, where a 1D-CFD simulation using a multi-sectional gird is performed. A very
good agreement is obtained at the experimental and the numerical validation levels.

Continuous fibre reinforced thermoplastics are a high competitive material class for
diversified applications because of their inherent properties like light-weight construction
potential, integral design, corrosion resistance and high energy absorption level.
Using these materials, one approach towards a large volume scaled part production
rate is covered by an automated process line, consisting of a pressing process for
semi-finised sheet material production, a thermoforming step and some additional
joining technologies. To allow short cycle times in the thermoforming step, the utilised
semi-finished sheet materials, which are often referred to as “organic sheets”, have
to be fully impregnated and consolidated.
Nowadays even this combination of outstanding physical and chemical material
properties combined with the economic processing technology are no guarantee for
the break-through of continuous fibre reinforced thermoplastics, mainly because of
the high material costs for the semi-finished sheet materials. These costs can be attributed
to a non adapted material selection or choice of process parameters, as well
as by unfavourable pressing process type itself.
Therefore the aim of the present investigations was to generate some alternatives
regarding the choice of raw materials, the set-up or the selection of the pressing
process line and to provide some theoretical tools for the determination of process
parameters and dimensions.
Concerning raw material aspects, the use of the blending technology is one promising
approach towards cost reduction for the matrix component. Novel characteristics
related to the fibre structure are CF-yarns with high filament numbers (e.g. 6K or 12K instead of 3K) or multiaxial fibre orientations. These two approaches were both conducted
for sheet materials with carbon fibre reinforcement and high temperature
thermoplastics.
Two new developed ternary blend matrices consisting of PEEK and PEI as the main
ingredients were tested in comparison with neat PEEK. PES and PSU were used as
the third blend component, which provides a cost reduction potential of approximately
30 % compared to the basis PEEK polymer. The results of the static pressing experiments
pointed out that the processing behaviour of the new blends is similar to
the neat PEEK matrix. A maximum process temperature of 410 °C should not be surpassed, otherwise thermal degradation will occur and will have a negative influence
on mechanical laminat properties. To accelerate the impregnation progress a
process pressure of 25 bar in combination with a sidewise opened tooling concept is
helpful. No differences were identified if film-stacking technique was substituted by
powder-prepreg-technology or vice versa. By increasing the yarn filament number
from 3K over 6K to 12K, which is equal to an increase in bundle diameter and therefore
transverse flow distance, the impregnation time has to be extended. If unspread
yarns are used, the risk of void entrapment rises tremendously, especially with 12K
and UD-structures. To reach full impregnation with a woven 6K-fabric, an increase of
process time of 20 to 30 % compared to a 3K textile structure is required. Furthermore,
it was shown that if only transverse flow is used for the impregnation of a UDstructure,
a maximum area weight of 300-400 g/m² should not be exceeded. Additionally,
the transport of air is strictly affected by the fibre orientation, because the
main amount of displaced air runs in longitudinal fibre direction. These facts play an
important role in the design of a multaxial laminat or an impregnation process for
such a structure and have to be taken into account.
Apart from these static pressing experiments the semi-continuous (stepwise compression
moulding) and continuous (double belt press processing) processing technology
were investigated and compared to each other. The first basic processing
trails on the stepwise compression moulding equipment were carried out with the material
system GF/PA66. Whereas the processing behaviour of this material combination
in a double belt press is known quite well, there is only little information about
semi-continuous processing. The performed trials pointed out that the resulting laminate
quality for both technologies only differs in the achievable local surface quality.
Mechanical laminate properties like three point bending stiffness and strength are
directly comparable. Due to the fact that there is only small experience with the stepwise
compression moulding process, potential improvements regarding surface Quality are feasible by adapting the step procedure and the temperature distribution within
the tooling concept. If laminates, produced by semi-continuous processing, are deployed
in a thermoforming process or in a non visible structural application, the surface
appearance only plays an inferior role.
The present results with high temperature thermoplastic matrices and CF do confirm
the positive assessment for the stepwise compression moulding technology, even though the mechanical laminate values have only reached 90 % of the data received
by static press processing. In comparison to the data from literature, 90 % is already
a high mechanical performance level. The results are quite promising for the use of
the semi-continuous technology, despite the process set-up and processing parameters
not being optimised. Furthermore there are tremendous advantages in processing
equipment costs.
Finally a process model was developed based on the experimental data pool. This
model can be characterised as a tool, which provides useful boundary conditions and
dimension values for the selection of a certain pressing process depending on the
desired material combination, laminate thickness and production output. The applicability
and accuracy of the model was proofed by a direct comparison between experimental
and calculated data.
First of all the temperature profile of the pressing process was generalised by a very
common structure. This profile reflects the main characteristics for the processing of
a thermoplastic composite material. Depending on the material combination, the
laminate thickness and the occurring heat transfers, several process- and processing-
portfolios were calculated. For a defined combination of the aforementioned parameters,
these portfolios directly provide the periods of time for heating and cooling
of the laminate structure. The last step is to convert these information into an equipment
dimension and to decide which machinery configuration fulfils these requirements.

The detection and characterisation of undesired lead structures on shaft surfaces is a concern in production and quality control of rotary shaft lip-type sealing systems. The potential lead structures are generally divided into macro and micro lead based on their characteristics and formation. Macro lead measurement methods exist and are widely applied. This work describes a method to characterise micro lead on ground shaft surfaces. Micro lead is known as the deviation of main orientation of the ground micro texture from circumferential direction. Assessing the orientation of microscopic structures with arc minute accuracy with regard to circumferential direction requires exact knowledge of both the shaft’s orientation and the direction of surface texture. The shaft’s circumferential direction is found by calibration. Measuring systems and calibration procedures capable of calibrating shaft axis orientation with high accuracy and low uncertainty are described. The measuring systems employ areal-topographic measuring instruments suited for evaluating texture orientation. A dedicated evaluation scheme for texture orientation is based on the Radon transform of these topographies and parametrised for the application. Combining the calibration of circumferential direction with the evaluation of texture orientation the method enables the measurement of micro lead on ground shaft surfaces.

The increasing parallelisation of development processes as well as the ongoing trends towards virtual product development and outsourcing of development activities strengthen the need for 3D co-operative design via communication networks. Regarding the field of CAx, none of the existing systems meets all the requirements of very complex process chain. This leads to a tremendous need for the integration of heterogeneous CAx systems. Therefore, MACAO, a platform-independent client for a distributed CAx component system, the so-called ANICA CAx object bus, is presented. The MACAO client is able to access objects and functions provided by different CAx servers distributed over a communication network. Thus, MACAO is a new solution for engineering design and visualisation in shared distributed virtual environments. This paper describes the underlying concepts, the actual prototype implementation, as well as possible application scenarios in the area of co-operative design and visualisation.

Das Problem der Integration heterogener Softwaresysteme stellt sich auch auf dem Gebiet der CAx-Systeme, wie sie in vielfältigen Ausprägungen etwa in der Automobilbranche für die Fahrzeugentwicklung eingesetzt werden. Zunächst werden die heute in diesem Bereich
praktizierten Lösungen und die dabei auftretenden Probleme kurz dargestellt. Danach werden der neue Standard für Produktdaten, STEP, und der Standard für die Interoperabilität heterogener Softwaresysteme, CORBA, sowie einige CORBA-Entwurfsmuster erläutert. Als nächstes wird eine auf diesen beiden Standards basierende CAx-Integrationsarchitektur, die im Projekt ANICA entwickelt wurde, vorgestellt und die prinzipielle Vorgehensweise bei
ihrer Realisierung beschrieben. Daran anschließend wird über eine erste Umsetzung dieser Architektur in die Praxis berichtet. Zum Abschluß wird kurz auf die gewonnenen Erfahrungen eingegangen und ein Ausblick auf zukünftige Entwicklungen gegeben.

Der Trend der letzten Jahre im CAx-Bereich geht eindeutig in Richtung 3D-Modellierung. Der Einsatz dieser Technologie ist jedoch erst dann wirtschaftlich sinnvoll, wenn die generierten Daten nicht ausschließlich als Ersatz für 2D-Zeichnungen dienen, sondern während des gesamten Produkt-entstehungsprozesses eingesetzt werden und auf diese Weise Datendurchgängigkeit gewährleistet wird. Mittlerweile wird ein umfangreiches Spektrum von Anwendungen eingesetzt. Beispielhaft sei-en hier Berechnungs- und Simulationsprogramme oder die 3D-Produktvisualisierung in nicht-technischen Bereichen (z. B. Marketing, Vertrieb) genannt. Viele CA-Systeme bieten zwar eine große Auswahl an Modulen für nahezu alle Bereiche der Produktentwicklung, allerdings ist kein System, unabhängig von seiner Komplexität, in der Lage, alle Anforderungen seiner Anwender zu erfüllen. Deshalb kommen in immer größerem Umfang spezielle Programme für individuelle Probleme zum Einsatz. Der Anwender sieht sich jedoch mit Schwierigkeiten konfrontiert, wenn er versucht, für spezielle Probleme spezielle Anwendungen unterschiedlicher Systemhersteller einzusetzen. Um die Integrati-on der verschiedenen Programme zu ermöglichen, muß er sich auf neutrale Standardschnittstellen für den Produktdatenaustausch (IGES, VDAFS, STEP) verlassen, wobei hier mit Informationsverlusten zu rechnen ist. Außerdem muß er sich mit differierenden Benutzerführungen vertraut machen. Im Bewußtsein dieser Probleme entwickelte die Arbeitsgruppe "CAD/CAM-Strategien der deut-schen Automobilindustrie" einen Vorschlag für eine offene CAx-Systemarchitektur /1/, /2/, /3/. Diese sollte in der Lage sein, alle CAx-Komponenten, die im Laufe des Produktent-stehungsprozesses verwendet werden, zu integrieren. Es sollte unter anderem die folgenden Anforderungen erfüllen: ° Offenheit ° Interoperabilität ° Investitionssicherheit ° Aufhebung der Zwangsbindung des Anwenders an einen Systemhersteller ° Vermeidung redundanter Systeme Die Berücksichtigung der internationalen Standards STEP für den Bereich der Produktdatenmo-dellierung und CORBA für den Bereich der verteilten objektorientierten Systeme, die in den folgen-den Abschnitten kurz dargestellt sind, war für die Erfüllung dieser Anforderungen eine wichtige Voraussetzung

Die virtuelle Produktentwicklung in verteilter Umgebung erfordert eine intensive Kommunika-tion zwischen den beteiligten CAx-Systemen. Diese findet bisher in Form des dateibasierten Datenaustausches mit Hilfe von Direktkonvertern oder neutralen Schnittstellen statt. Der Datenaustausch wird hierbei meist in mehreren Iterationsschleifen durchgeführt und ist oft mit Datenverlusten sowie Unterbrechungen der Entwicklungsaktivitäten verbunden. Demgegenüber steht als neuer Ansatz für die Interoperabilität zwischen CAx-Systemen das Konzept eines CAx-Objektbusses auf Basis von CORBA und STEP. Dieser Ansatz ermög-licht eine plattformübergreifende Online-Kopplung heterogener CAx-Systeme. Im Gegensatz zum dateibasierten Datenaustausch ist hierbei ein transparenter Zugriff sowohl auf Daten als auch auf Funktionen der angebundenen Systeme möglich. Dadurch kann die Durchgängigkeit der Produktdaten in der Prozeßkette deutlich erhöht werden. Zur Beurteilung der Praxistauglichkeit wird dieser neue Ansatz dem dateibasierten Daten-austausch am Beispiel virtueller Einbauuntersuchungen gegenübergestellt. Dabei werden für unterschiedliche praxisrelevante Modellgrößen die für die Übertragung von Geometrie und Topologie erforderlichen Zeiten analysiert und verglichen. Weiterhin werden die generellen Vor- und Nachteile der beiden Lösungen dargestellt. Abschließend wird auf die Potentiale des neuen Ansatzes für den Einsatz in anderen Bereichen eingegangen.

Interoperability between different CAx systems involved in the development process of cars is presently one of the most critical issues in the automotive industry. None of the existing CAx systems meets all requirements of the very complex process network of the lifecycle of a car. With this background, industrial engineers have to use various CAx systems to get an optimal support for their daily work. Today, the communication between different CAx systems is done via data files using special direct converters or neutral system independent standards like IGES, VDAFS, and recently STEP, the international standard for product data description. To reduce the dependency on individual CAx s ystem vendors, the German automotive industry developed an open CAx system architecture based on STEP as guiding principle for CAx system development. The central component of this architecture is a common, system-independent access interface to CAx functions and data of all involved CAx systems, which is under development in the project ANICA. Within this project, a CAx object bus has been developed based on a STEP data description using CORBA as an integration platform. This new approach allows a transparent access to data and functions of the integrated CAx systems without file-based data exchange. The product development process with various CAx systems concerns objects from different CAx systems. Thus, mechanisms are needed to handle the persistent storage of the CAx objects distributed over the CAx object bus to give the developing engineers a consistent view of the data model of their product. The following paper discusses several possibilities to guarantee consistent data management and storage of distributed CAx models. One of the most promising approaches is the enhancement of the CAx object bus by a STEP-based object-oriented data server to realise a central data management.

Today, the worlds and terminologies of mechanical engineering and software engineering coexist, but they do not always work together seamlessly. Both worlds have developed their own separate formal vocabulary for expressing their concepts as well as for capturing and communicating their respective domain knowledge. But, these two vocabularies are not unified, interwoven, or at least interconnected in a reasonable manner. Thus, the subject of this paper is a comparison of the vocabularies of the two fields, namely feature technology from the area of mechanical engineering and software design patterns from the software engineering domain. Therefore, a certain amount of definitions, history, examples, etc. is presented for features as well as for design patterns. After this, an analysis is carried out to identify analogies and differences. The main intention of this paper is to inform both worlds - mechanical and software engineering - about the other side's terminology and to start a discussion about potential mutual benefits and possibilities to bridge the gap between these two worlds, e.g. to improve the manageability of CAx product development processes.

Einfluss verschiedener Angussszenarien auf den Harzinjektionsprozess und dessen simulative Abbildung
(2014)

Die Herstellung von hochleistungs Kunststoff Verbunden für Strukturbauteile erfolgt
in der Automobilindustrie mittels Resin Transfer Molding (RTM), wobei die Kosten für
die Bauteile sehr hoch sind. Die Kosten müssen durch Prozessoptimierungen deutlich
reduziert werden, um eine breite Anwendung von faserverstärkten Kunststoff
Verbunde zu ermöglichen. Prozesssimulationen spielen hierbei eine entscheidende
Rolle, da zeitaufwendige und kostspielige Praxisversuche ersetzt werden können.
Aus diesem Grund wurden in dieser Arbeit die Potentiale der simulativen Abbbildung
des RTM-Prozesses untersucht. Basis der Simulationen bildete eine umfangreiche
Materialparameterstudie bei der die Permeabilität, von für die Automobilindustrie relevanten
Textilhalbzeugen im ungescherten und gescherten Zustand, untersucht
wurde. Somit konnte der Einfluss von Drapierung bei der Fließsimulation evaluiert
werden. Zudem wurde eine neue Methode zur Ermittlung der zeit-, vernetzungs- und
temperaturabhängigen Viskositätsverläufe von hochreaktiven Harzsystemen entwickelt
und angewendet. Die Fließsimulationsmethode wurde zunächst erfolgreich an
einem ebenen Plattenwerkzeug validiert, um zu zeigen, dass die ermittelten Materialparameter
korrekt bestimmt wurden.
Zur Validierung der Simulation wurde ein komplexes Technologieträgerwerkzeug
(TTW) entwickelt. Die Auslegung der Temperierung wurde mittels Temperiersimulationen
unterstützt. Untersuchungen an markanten Kantenbereichen, wie sie bei Automobilbauteilen
häufig auftreten, haben gezeigt, dass bei Kantenradien < 5 mm ein
Voreilen des Harzsystem zu beachten ist. Zudem konnte mittels verschiedener Angussleisten,
der Einfluss verschiedener Angussszenarien untersucht werden.
Mit Hilfe von Sensoren im TTW wurden die Prozessdaten protokolliert und anschließend
mit den Simulationen verglichen. Die Ergebnisse zeigen, dass die simulative
Abbildung des Füllprozesses bei einem komplexen RTM-Werkzeug, trotz einer Vielzahl
an Prozesseinflüssen, möglich ist. Die Abweichungen zwischen der Simulation
und dem Versuch lagen teilweise unter 15 %. Die Belastbarkeit der ermittelten Permeabilitäts-
und Viskositätswerte wurde dadurch nochmals bestätigt. Zudem zeigte
sich, dass die Angussleistenlänge einen signifikanten Einfluss auf die Prozesszeit
hat, wohingegen der Angussleistenquerschnitt eine untergeordnete Rolle spielt.

Within the last decades, a remarkable development in materials science took place -- nowadays, materials are not only constructed for the use of inert structures but rather designed for certain predefined functions. This innovation was accompanied with the appearance of smart materials with reliable recognition, discrimination and capability of action as well as reaction. Even though ferroelectric materials serve smartly in real applications, they also possess several restrictions at high performance usage. The behavior of these materials is almost linear under the action of low electric fields or low mechanical stresses, but exhibits strong non-linear response under high electric fields or mechanical stresses. High electromechanical loading conditions result in a change of the spontaneous polarization direction with respect to individual domains, which is commonly referred to as domain switching. The aim of the present work is to develop a three-dimensional coupled finite element model, to study the rate-independent and rate-dependent behavior of piezoelectric materials including domain switching based on a micromechanical approach. The proposed model is first elaborated within a two-dimensional finite element setting for piezoelectric materials. Subsequently, the developed two-dimensional model is extended to the three-dimensional case. This work starts with developing a micromechanical model for ferroelectric materials. Ferroelectric materials exhibit ferroelectric domain switching, which refers to the reorientation of domains and occurs under purely electrical loading. For the simulation, a bulk piezoceramic material is considered and each grain is represented by one finite element. In reality, the grains in the bulk ceramics material are randomly oriented. This property is taken into account by applying random orientation as well as uniform distribution for individual elements. Poly-crystalline ferroelectric materials at un-poled virgin state can consequently be characterized by randomly oriented polarization vectors. Energy reduction of individual domains is adopted as a criterion for the initiation of domain switching processes. The macroscopic response of the bulk material is predicted by classical volume-averaging techniques. In general, domain switching does not only depend on external loads but also on neighboring grains, which is commonly denoted as the grain boundary effect. These effects are incorporated into the developed framework via a phenomenologically motivated probabilistic approach by relating the actual energy level to a critical energy level. Subsequently, the order of the chosen polynomial function is optimized so that simulations nicely match measured data. A rate-dependent polarization framework is proposed, which is applied to cyclic electrical loading at various frequencies. The reduction in free energy of a grain is used as a criterion for the onset of the domain switching processes. Nucleation in new grains and propagation of the domain walls during domain switching is modeled by a linear kinetics theory. The simulated results show that for increasing loading frequency the macroscopic coercive field is also increasing and the remanent polarization increases at lower loading amplitudes. The second part of this work is focused on ferroelastic domain switching, which refers to the reorientation of domains under purely mechanical loading. Under sufficiently high mechanical loading, however, the strain directions within single domains reorient with respect to the applied loading direction. The reduction in free energy of a grain is used as a criterion for the domain switching process. The macroscopic response of the bulk material is computed for the hysteresis curve (stress vs strain) whereby uni-axial and quasi-static loading conditions are applied on the bulk material specimen. Grain boundary effects are addressed by incorporating the developed probabilistic approach into this framework and the order of the polynomial function is optimized so that simulations match measured data. Rate dependent domain switching effects are captured for various frequencies and mechanical loading amplitudes by means of the developed volume fraction concept which relates the particular time interval to the switching portion. The final part of this work deals with ferroelectric and ferroelastic domain switching and refers to the reorientation of domains under coupled electromechanical loading. If this free energy for combined electromechanical loading exceeds the critical energy barrier elements are allowed to switch. Firstly, hysteresis and butterfly curves under purely electrical loading are discussed. Secondly, additional mechanical loads in axial and lateral directions are applied to the specimen. The simulated results show that an increasing compressive stress results in enlarged domain switching ranges and that the hysteresis and butterfly curves flatten at higher mechanical loading levels.

Wetting of a solid surface with liquids is an important parameter in the chemical engineering process such as distillation, absorption and desorption. The degree of wetting in packed columns mainly contributes in the generating of the effective interfacial area and then enhancing of the heat and mass transfer process. In this work the wetting of solid surfaces was studied in real experimental work and virtually through three dimensional CFD simulations using the multiphase flow VOF model implemented in the commercial software FLUENT. That can be used to simulate the stratified flows [1]. The liquid rivulet flow which is a special case of the film flow and mostly found in packed columns has been discussed. Wetting of a solid flat and wavy metal plate with rivulet liquid flow was simulated and experimentally validated. The local rivulet thickness was measured using an optically assisted mechanical sensor using a needle which is moved perpendicular to the plate surface with a step motor and in the other two directions using two micrometers. The measured and simulated rivulet profiles were compared to some selected theoretical models founded in the literature such as Duffy & Muffatt [2], Towell & Rothfeld [3] and Al-Khalil et al. [4]. The velocity field in a cross section of a rivulet flow and the non-dimensional maximum and mean velocity values for the vertical flat plate was also compared with models from Al-Khalil et al. [4] and Allen & Biggin [5]. Few CFD simulations for the wavy plate case were compared to the experimental findings, and the Towel model for a flat plate [3]. In the second stage of this work 3-D CFD simulations and experimental study has been performed for wetting of a structured packing element and packing sheet consisting of three elements from the type Rombopak 4M, which is a product of the company Kuhni, Switzerland. The hydrodynamics parameters of a packed column, e. i. the degree of wetting, the interfacial area and liquid hold-up have been depicted from the CFD simulations for different liquid systems and liquid loads. Flow patterns on the degree of wetting have been compared to that of the experiments, where the experimental values for the degree of wetting were estimated from the snap shooting of the flow on the packing sheet in a test rig. A new model to describe the hydrodynamics of packed columns equipped with Rombopak 4M was derived with help of the CFD–simulation results. The model predicts the degree of wetting, the specific or interfacial area and liquid hold-up at different flow conditions. This model was compared to Billet & Schultes [6], the SRP model Rocha et al. [7-9], to Shi & Mersmann [10] and others. Since the pressure drop is one of the most important parameter in packed columns especially for vacuum operating columns, few CFD simulations were performed to estimate the dry pressure drop in a structured and flat packing element and were compared to the experimental results. It was found a good agreement from one side, between the experimental and the CFD simulation results, and from the other side between the simulations and theoretical models for the rivulet flow on an inclined plate. The flow patterns and liquid spreading behaviour on the packing element agrees well with the experimental results. The VOF (Volume of Fluid) was found very sensitive to different liquid properties and can be used in optimization of the packing geometries and revealing critical details of wetting and film flow. An extension of this work to perform CFD simulations for the flow inside a block of the packing to get a detailed picture about the interaction between the liquid and packing surfaces is recommended as further perspective.

The polydispersive nature of the turbulent droplet swarm in agitated liquid-liquid contacting equipment makes its mathematical modelling and the solution methodologies a rather sophisticated process. This polydispersion could be modelled as a population of droplets randomly distributed with respect to some internal properties at a specific location in space using the population balance equation as a mathematical tool. However, the analytical solution of such a mathematical model is hardly to obtain except for particular idealized cases, and hence numerical solutions are resorted to in general. This is due to the inherent nonlinearities in the convective and diffusive terms as well as the appearance of many integrals in the source term. In this work two conservative discretization methodologies for both internal (droplet state) and external (spatial) coordinates are extended and efficiently implemented to solve the population balance equation (PBE) describing the hydrodynamics of liquid-liquid contacting equipment. The internal coordinate conservative discretization techniques of Kumar and Ramkrishna (1996a, b) originally developed for the solution of PBE in simple batch systems are extended to continuous flow systems and validated against analytical solutions as well as published experimental droplet interaction functions and hydrodynamic data. In addition to these methodologies, we presented a conservative discretization approach for droplet breakage in batch and continuous flow systems, where it is found to have identical convergence characteristics when compared to the method of Kumar and Ramkrishna (1996a). Apart from the specific discretization schemes, the numerical solution of droplet population balance equations by discretization is known to suffer from inherent finite domain errors (FDE). Two approaches that minimize the total FDE during the solution of the discrete PBEs using an approximate optimal moving (for batch) and fixed (for continuous systems) grids are introduced (Attarakih, Bart & Faqir, 2003a). As a result, significant improvements are achieved in predicting the number densities, zero and first moments of the population. For spatially distributed populations (such as extraction columns) the resulting system of partial differential equations is spatially discretized in conservative form using a simplified first order upwind scheme as well as first and second order nonoscillatory central differencing schemes (Kurganov & Tadmor, 2000). This spatial discretization avoids the characteristic decomposition of the convective flux based on the approximate Riemann Solvers and the operator splitting technique required by classical upwind schemes (Karlsen et al., 2001). The time variable is discretized using an implicit strongly stable approach that is formulated by careful lagging of the nonlinear parts of the convective and source terms. The present algorithms are tested against analytical solutions of the simplified PBE through many case studies. In all these case studies the discrete models converges successfully to the available analytical solutions and to solutions on relatively fine grids when the analytical solution is not available. This is accomplished by deriving five analytical solutions of the PBE in continuous stirred tank and liquid-liquid extraction column for especial cases of breakage and coalescence functions. As an especial case, these algorithms are implemented via a windows computer code called LLECMOD (Liquid-Liquid Extraction Column Module) to simulate the hydrodynamics of general liquid-liquid extraction columns (LLEC). The user input dialog makes the LLECMOD a user-friendly program that enables the user to select grids, column dimensions, flow rates, velocity models, simulation parameters, dispersed and continuous phases chemical components, and droplet phase space-time solvers. The graphical output within the windows environment adds to the program a distinctive feature and makes it very easy to examine and interpret the results very quickly. Moreover, the dynamic model of the dispersed phase is carefully treated to correctly predict the oscillatory behavior of the LLEC hold up. In this context, a continuous velocity model corresponding to the manipulation of the inlet continuous flow rate through the control of the dispersed phase level is derived to get rid of this behavior.

Liquid Composite Molding (LCM) processes, like Resin Transfer Molding (RTM) and Vacuum Assisted Resin Infusion (VARI), are gaining increasing interest for the cost-efficient production of fiber reinforced polymer matrix composites, e. g. Airbus A380 rear bulkhead. Meanwhile, purpose-built thermoset resin systems with adequately low processing viscosities are available. Although showing a better fatigue resistance composites from epoxy resins (EP) tend to be expensive while vinylester resin (VE) composites are more brittle and, hence, less fatigue resistant but attract due to their lower material costs. Following research on the toughness improvement of vinylester based resin systems, one subject of this thesis was the broad experimental characterization of the static and cyclic behavior of carbon fiber reinforced composites from resin systems which were toughened by either the generation of interpenetrating networks with aliphatic (Al-EP) and cyclo-aliphatic epoxy resins (Cal-EP) or by addition of a liquid, epoxy-terminated butadiene-nitrile rubber (ETBN). While quasi-static in-plane tension, compression and shear testing of [0°]8 and [±45°]3S laminates resulted in an unclear picture with regard to the mechanical performance of the investigated resin systems, R = -1 cyclic step loading provided a definite indication of the considerably higher cyclic fatigue strength of the modified carbon fiber reinforced vinylester-urethane (CF/VEUH:ETBN) composite which, consequently, was selected for detailed mechanical testing. To provide experimental input for subsequent fatigue life simulations applying the Critical Element Concept of Reifsnider et al. [76] the study included the determination of ultimate in-plane tension, compression and shear properties as well as the characterization of the cyclic fatigue behavior under constant amplitude loading. Different descriptions of S-N curves of the [0°]8-, [0°/90°]2S- and [+45°/0°/-45°/90°]S-laminates for R = +0.1, -1 and +10 were determined to derive constant fatigue life diagrams applying methods of Goodman or Harris et al. Furthermore the residual strength degradation model for the critical element (0° ply) and the residual stiffness degradation models for the sub-critical elements have been derived by experimental determination on [0°]8-, [0°/90°]2S- and [+45°/0°/-45°/90°]S-(CF/VEUH:ETBN)-laminates. Deficiencies in current fatigue life time prediction modeling for carbon fiber reinforced materials nowadays results in large factors of safety to be adopted. As a consequence composite structures are often overdesigned and expensive proto-type testing is required for life time prediction. Therefore, in this thesis standardized random-ordered miniTWIST (minimized transport wing standard) spectrum loading was used to understand improvements in fatigue life modeling so that fatigue life prediction results in a more efficient use of these materials. In particular the influence of constant amplitude cyclic fatigue modeling as well as constant fatigue life modeling itself on the results of the fatigue life analysis of random loading sequences have been investigated. Finally the bearing of residual strength or residual stiffness degradation modeling and the effect of filtering and counting methods on the fatigue life time prediction was determined in a sensitivity analysis. The fatigue life models were validated by experimental results using the random miniTWIST-loading on [0°]8-, [0°/90°]2S- and [+45°/0°/-45°/90°]S-(CF/VEUH:ETBN)-laminates.

The extraction kinetics of polyphenols, which are leached from red vine leaves, are studied and evaluated using a laboratory robot and nonconventional processing techniques such as ultrasonic (US)-, microwave (MW)-, and pulsed electric field (PEF)-assisted extraction processes. The robotic high-throughput screening reveals optimal extraction conditions at a pH value of 2.5, a temperature of 56 °C, and a solvent mixture of methanol:water:HCl of 50:49:1 v/v/v. Nonconventional processing techniques, such as MW- and US-assisted extraction, have the fastest kinetics and produce the highest polyphenol yield. The non-conventional techniques yield is 2.29 g/L (MW) resp. 2.47 g/L (US) for particles that range in size from 450 to 2000 µm and 2.20 g/L (MW) resp. 2.05 g/L (US) for particles that range from 2000 to 4000 µm. PEF has the lowest yield of polyphenols with 0.94 g/L (450–2000 µm), resp. 0.64 g/L (2000–4000 µm) in comparison to 1.82 g/L (2000 to 4000 µm) in a standard stirred vessel (50 °C). When undried red vine leaves (2000 to 4000 µm) are used the total phenol content is 1.44 g/L with PEF.

Epoxy belongs to a category of high-performance thermosetting polymers which have been used extensively in industrial and consumer applications. Highly cross-linked epoxy polymers offer excellent mechanical properties, adhesion, and chemical resistance. However, unmodified epoxies are prone to brittle fracture and crack propagation due to their highly crosslinked structure. As a result, epoxies are normally toughened to ensure the usability of these materials in practical applications.
This research work focuses on the development of novel modified epoxy matrices, with enhanced mechanical, fracture mechanical and thermal properties, suitable to be processed by filament winding technology, to manufacture composite based calender roller covers with improved performance in comparison to commercially available products.
In the first stage, a neat epoxy resin (EP) was modified using three different high functionality epoxy resins with two type of hardeners i.e. amine-based (H1) and anhydride-based (H2). Series of hybrid epoxy resins were obtained by systematic variation of high functionality epoxy resin contents with reference epoxy system. The resulting matrices were characterized by their tensile properties and the best system was chosen from each hardener system i.e. amine and anhydride. For tailored amine based system (MEP_H1) 14 % improvement was measured for bulk samples similarly, for tailored anhydride system (MEP_H2) 11 % improvement was measured when tested at 23 °C.
Further, tailored epoxy systems (MEP_H1 and MEP_H2) were modified using specially designed block copolymer (BCP), and core-shell rubber nanoparticles (CSR). Series of nanocomposites were obtained by systematic variation of filler contents. The resulting matrices were extensively characterized qualitatively and quantitatively to reveal the effect of each filler on the polymer properties. It was shown that the BCP confer better fracture properties to the epoxy resin at low filler loading without losing the other mechanical properties. These characteristics were accompanied by ductility and temperature stability. All composites were tested at 23 °C and at 80 °C to understand the effect of temperature on the mechanical and fracture properties.
Examinations on fractured specimen surfaces provided information about the mechanisms responsible for reinforcement. Nanoparticles generate several energy dissipating mechanisms in the epoxy, e.g. plastic deformation of the matrix, cavitation, void growth, debonding and crack pinning. These were closely related to the microstructure of the materials. The characteristic of the microstructure was verified by microscopy methods (SEM and AFM). The microstructure of neat epoxy hardener system was strongly influenced by the nanoparticles and the resulting interfacial interactions. The interaction of nanoparticles with a different hardener system will result in different morphology which will ultimately influence the mechanical and fracture mechanical properties of the nanocomposites. Hybrid toughening using a combination of the block-copolymer / core-shell rubber nanoparticles and block copolymer / TiO2 nanoparticles has been investigated in the epoxy systems. It was found out that addition of rigid phase with a soft phase recovers the loss of strength in the nanocomposites caused by a softer phase.
In order to clarify the relevant relationships, the microstructural and mechanical properties were correlated. The Counto’s, Halpin-Tsai, and Lewis-Nielsen equations were used to calculate the modulus of the composites and predicted modulus fit well with the measured values. Modeling was done to predict the toughening contribution from block copolymers and core-shell rubber nanoparticles. There was good agreement between the predicted values and the experimental values for the fracture energy.