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Élaboration de carbures cémentés à gradient de propriétés par procédé d’imbibition réactive : Application aux inserts WC-Co et aux taillants en diamant polycristallin pour le forage pétrolier en conditions sévères / Functionally graded cemented carbides elaboration by reactive imbibition process : Application for WC-Co inserts and PDC cutters for oil drilling in harsh conditionsTher, Olivier 16 December 2014 (has links)
Dans l'industrie du forage pétrolier, les conditions de travail de plus en plus sévères requièrent sans cesse de nouveaux outils plus résistants à l'usure abrasive et à l'impact. Afin de répondre à ce défi, les travaux présentés ici, ont pour but l'élaboration de matériaux en carbure cémenté à gradient de composition par le procédé d'imbibition réactive. Ce procédé peut être décomposé en deux procédés de gradation, à savoir : l'imbibition et le revêtement réactif. L'imbibition a pour rôle d'enrichir graduellement, en phase liante, le coeur d'une pièce en carbure cémenté dense et repose sur le principe de migration de phase liquide dans un corps solide-liquide. Le revêtement réactif est un procédé qui s'applique également sur un carbure cémenté dense sur lequel est déposé un revêtement de nitrure de bore. Après avoir atteint le liquidus de la phase liante du carbure cémenté, une précipitation de borures ternaires prend place à la surface du matériau et s'étend graduellement sur des distances millimétriques. Dans le cas de pièces industrielles (inserts tricône et supports de taillants PDC (Polycrystalline Diamond Compact)), le traitement d'imbibition réactive permet de générer des gradients de dureté pouvant atteindre 450 HV sur 25 mm. L'élaboration de tels gradients a nécessité une meilleure compréhension des cinétiques ainsi que des phénomènes mis en jeu durant l'imbibition et le revêtement réactif. Dans le cas des taillants PDC, l'influence des paramètres du procédé HPHT de synthèse de la plaquette diamantée, sur le gradient de composition présent dans le support WC-Co après imbibition réactive, a été étudiée. Ces travaux se sont également intéressés à l'effet de ces gradients de composition sur les propriétés des plaquettes diamantées ainsi obtenues. A la suite d'essais mécaniques, les inserts WC-Co et taillants PDC gradués montrent une augmentation significative de leur résistance à l'abrasion (de 30 à 100%) et de leur tenue à l'impact (de 20 à 40%). / In oil drilling industry, harsher working conditions require ever new and more abrasive wear and impact resistant tools. To meet this challenge, the work presented here, is to develop graded cemented carbide materials by reactive imbibition process. This method can be divided into two gradation processes, namely, reactive coating and imbibition. Imbibition gradually enriches the core of dense cemented carbide with binder phase and is based on the principle of liquid phase migration in a solid-liquid body. Reactive coating also takes place in dense cemented carbide on which a boron nitride coating is deposited. After reaction with the WC-Co liquid binder, some ternary boride precipitations take place from surface to several millimeters deep. For industrial parts (inserts for roller cone bits and PDC (Polycrystalline Diamond Compact) cutters substrates), hardness gradients obtained can reach 450 HV on 25 mm. Such gradients development is passed through a better understanding of kinetics and phenomena occurring during imbibition and reactive coating. In case of PDC cutters, influence of HPHT process parameters, allowing diamond table synthesis, on the WC-Co substrate gradient, generated by reactive imbibition, was studied. This work was also interested in gradient effect on the obtained diamond tables properties. After mechanical tests, graded WC-Co inserts and graded PDC cutters show a significant increase of both wear resistance (from 30 to 100%) and impact resistance (from 20 to 40%).
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[en] THE SIMPLIFIED HYBRID BOUNDARY ELEMENT METHOD APPLIED TO TIME DEPENDENT PROBLEMS / [pt] O MÉTODO HÍBRIDO SIMPLIFICADO DOS ELEMENTOS DE CONTORNO APLICADO A PROBLEMAS DEPENDENTES DO TEMPORICARDO ALEXANDRE PASSOS CHAVES 22 March 2004 (has links)
[pt] O Método Híbrido dos Elementos de Contorno foi introduzido
em 1987. Desde então, o método foi aplicado com sucesso a
diferentes tipos de problemas de elasticidade e potencial,
inclusive problemas dependentes do tempo. Esta Tese
apresenta uma tentativa para consolidar a formulação
simplificada do Método Híbrido dos Elementos de Contorno
para a análise geral da resposta dinâmica de sistemas
elásticos. Baseado em um método de superposição modal, um
conjunto acoplado de equações diferenciais de movimento de
alta ordem é transformado em um conjunto desacoplado de
equações diferenciais de segunda ordem que podem ser
integradas normalmente por meio de procedimentos
conhecidos. Este método também é uma extensão de uma
formulação introduzida por J. S. Przemieniecki, para a
análise de vibração livre de barras e elementos de viga
baseada em uma série de freqüências. O método trata
estruturas restringidas, com condições iniciais não
homogêneas dadas como valores nodais e também através de
campos prescritos no domínio, assim como forças genéricas
de massa (além de forças inerciais). Esta tese também tem
por objetivo estabelecer a consolidação conceitual da
aplicação da versão simplificada do Método Híbrido dos
Elementos de Contorno a materiais com gradação funcional.
São obtidas várias classes de soluções fundamentais para
problemas de potencial dependentes e independentes do
tempo, para a análise no domínio da freqüência combinada
com uma técnica avançada (mencionada acima) de superposição
modal baseada em séries de freqüências. Com isso, consegue-
se a utilização de integrais somente no contorno mesmo para
materiais heterogêneos. Apresenta-se um grande número de
resultados numéricos de problemas bidimensionais, para
validação dos desenvolvimentos teóricos realizados. / [en] The hybrid boundary element method was introduced in 1987.
Since then, the method has been successfully applied to
different problems of elasticity and potential, including
time-dependent problems. This thesis presents an attempt to
consolidate a formulation for the general analysis of the
dynamic response of elastic systems. Based on a mode-
superposition technique, a set of coupled, higher-order
differential equations of motion is transformed into a set
of uncoupled second order differential equations, which may
be integrated by means of standard procedures. The first
motivation for these theoretical developments is the hybrid
boundary element method, a generalization of T. H. H.
Pian`s previous achievements for finite elements, which,
requiring only boundary integrals, yields a stiffness
matrix for arbitrary domain shapes and any number of
degrees of freedom. The method is also an extension of a
formulation introduced by J. S. Przemieniecki, for the free
vibration analysis of bar and beam elements based on a
power series of frequencies. It handles constrained and
unconstrained structures, non-homogeneous initial
conditions given as nodal values as well as prescribed
domain fields and general domain forces (other than
inertial forces). This thesis also focuses on establishing
the conceptual framework for applying the simplified
version of the hybrid boundary element method to
functionally graded materials. Several classes of
fundamental solutions for steady-state and time-dependent
problems of potential are derived for a frequency-domain
analysis combined with an advanced mode superposition
technique based on a power series of frequencies. Thus, the
boundary-only feature of the method is preserved even with
such spatially varying material property.Several numerical
examples are given in terms of an efficient patch test for
irregular bounded, unbounded and multiply connected regions
submitted to high gradients.
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ADDITIVE MANUFACTURING OF VISCOUS MATERIALS: DEVELOPMENT AND CHARACTERIZATION OF 3D PRINTED ENERGETIC STRUCTURESMonique McClain (9178199) 28 July 2020 (has links)
<p>The performance of solid rocket
motors (SRMs) is extremely dependent on propellant formulation, operating
pressure, and initial grain geometry. Traditionally, propellant grains are cast
into molds, but it is difficult to remove the grains without damage if the geometry
is too complex. Cracks or voids in propellant can lead to erratic burning that
can break the grain apart and/or potentially overpressurize the motor. Not only
is this dangerous, but the payload could be destroyed or lost. Some geometries
(i.e. internal voids or intricate structures) cannot be cast and there is no
consistent nor economical way to functionally grade grains made of multiple propellant
formulations at fines scales (~ mm) without the risk of delamination between
layers or the use of adhesives, which significantly lower performance. If one
could manufacture grains in such a way, then one would have more control and
flexibility over the design and performance of a SRM. However, new
manufacturing techniques are required to enable innovation of new propellant
grains and new analysis techniques are necessary to understand the driving
forces behind the combustion of non-traditionally manufactured propellant.</p>
<p>Additive manufacturing (AM) has
been used in many industries to enable rapid prototyping and the construction
of complex hierarchal structures. AM of propellant is an emerging research area,
but it is still in its infancy since there are some large challenges to
overcome. Namely, high performance propellant requires a minimum solids loading
in order to combust properly and this translates into mixtures with high
viscosities that are difficult to 3D print. In addition, it is important to be
able to manufacture realistic propellant formulations into grains that do not
deform and can be precisely functionally graded without the presence of defects
from the printing process. The research presented in this dissertation
identifies the effect of a specific AM process called Vibration Assisted
Printing (VAP) on the combustion of propellant, as well as the development of
binders that enable UV-curing to improve the final resolution of 3D printed structures.
In addition, the combustion dynamics of additively manufactured layered
propellant is studied with computational and experimental methods. The work
presented in this dissertation lays the foundation for progress in the
developing research area of additively manufactured energetic materials. </p>
<p>The appendices of this dissertation
presents some additional data that could also be useful for researchers. A more
detailed description of the methods necessary to support the VAP process,
additional viscosity measurements and micro-CT images of propellant, the
combustion of Al/PVDF filament in windowed propellant at pressure, and microexplosions
of propellant with an Al/Zr additive are all provided in this section. </p>
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Analisis de vibracion de vigas funcionalmente graduadas aplicando el metodo de elemento finitosMarquina Chamorro, Benjamín Flaviano, Dominguez Chávez, Juan Pablo 22 October 2020 (has links)
El presente trabajo, tiene como objetivo el estudio de la vibración libre de vigas Timoshenko aplicados a materiales funcionalmente graduados; esto se resuelve utilizando el método de elementos finitos (MEF) , al implementarlo en el software MATLAB, con el fin de obtener las frecuencias fundamentales y las gráficas de los modos de vibración para cada caso.
Se define el campo de desplazamientos según la teoría Timoshenko considerando tres variables fundamentales; asimismo, se utiliza el Principio de Hamilton para obtener las vibraciones libres del elemento. Para el desarrollo de las relaciones constitutivas se usa la La ley de potencia, el cual describe como varían las propiedades de un material heterogéneo e isotrópico FGM (FGM por sus siglas en inglés) en el peralte de la viga.
Los resultados obtenidos se compararon con otros estudios de la literatura validados por revistas como SCOPUS y SPRINGER, demostrando que el modelo es bastante preciso y satisfactorio. / The present work aims to study the free vibration of Timoshenko beams applied to functionally graduated materials; This is solved using the finite element method (FEM), when implemented in the MATLAB software, in order to obtain the fundamental frequencies and the graphs of the vibration modes for each case.
The field of displacements is defined according to the Timoshenko theory considering three fundamental variables; likewise, the Hamilton Principle is used to obtain the free vibrations of the element. For the development of the constitutive relationships, the power law is used, which describes how the properties of a heterogeneous and isotropic material FGM vary in the heightn of the beam.
The results obtained were compared with other literature studies validated by journals such as SCOPUS and SPRINGER, showing that the model is quite accurate and satisfactory. / Tesis
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Mechanical behaviors of bio-inspired composite materials with functionally graded reinforcement orientation and architectural motifsDi Wang (8782580) 01 May 2020 (has links)
<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>
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Referenční vokalizace papouška žako kongo (Psittacus erithacus) / Reference vocalization in African grey parrot (Psittacus erithacus)Brojerová, Jana January 2013 (has links)
The ability to communicate referentially has been historically viewed as being uniquelly human. However, with the increasing amount of studies discussing the communicative faculty of animals in the context of the evolution of human language, there is now growing evidence that this ability is present in many animal species, too. Although we know a lot about mimetic abilities of domesticated African grey parrots' (Psittacus erithacus) and their competence to use human words in a referential way, we know very little about the elements of referentiality in their natural vocalization. Our goal in this work was to find, whether and in which context is functionally referential vocalization in this species of birds present. We were determining its presence by the experiment, in which we have exposed four captured African grey parrot, in the ownership of FHS UK Prague, to stimuli that in other animal species usually elicit functionally referential vocalization: predators and prefered type of food. We analysed the behaviour and vocalizations of the tested birds by analytic softwares Interact, respectively Soundforge 0.8. We find out, that despite the fact that birds reaponded to our experimental objects appropriatelly (i.e. "predators" caused more fear and the like), they give the major amout of...
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[pt] DESENVOLVIMENTO DE ELEMENTOS FINITOS HÍBRIDOS PARA A ANÁLISE DE PROBLEMAS DINÂMICOS USANDO SUPERPOSIÇÃO MODAL AVANÇADA / [en] DEVELOPMENT OF HYBRID FINITE ELEMENTS FOR ANALYSIS OF DYNAMICS PROBLEMS USING ADVANCED MODE SUPERPOSITIONPLINIO GLAUBER CARVALHO DOS PRAZERES 02 January 2006 (has links)
[pt] O método híbrido de elementos finitos, proposto por Pian
com base no
potencial de Hellinger-Reissner, provou ser um avanço
conceitual entre as
formulações de discretização, tendo sido explorado
extensivamente desde então
por códigos acadêmicos e comerciais, também levando em
conta uma série
independente dos mais recentes desenvolvimentos chamados
métodos de
Trefftz. O método híbrido de elementos de contorno é uma
generalização bem
sucedida da formulação original de Pian, em que funções de
Green são usadas
como funções de interpolação no domínio, possibilitando
assim a modelagem
robusta e precisa de formas arbitrárias submetidas a
vários tipos de ações.Mais
recentemente, uma proposição de Przemieniecki - para a
análise geral de
vibração livre de elementos de treliça e viga - foi
incorporada à formulação de
elementos híbridos de contorno e estendida para a análise
de problemas
dependentes do tempo fazendo uso de um processo de
superposição modal
avançada que leva em conta condições iniciais gerais assim
como ações de
corpo gerais, além de efeitos inerciais. A presente
contribuição pretende trazer
para elementos finitos os melhoramentos conceituais
obtidos no contexto do
método híbrido de elementos de contorno. Uma grande
família de macro
elementos finitos híbridos é introduzida para o tratamento
unificado em 2D e 3D,
de problemas estáticos e transientes de elasticidade e
potencial com base nas
soluções fundamentais não-singulares. É também mostrado
que materiais nãohomogêneos,
como os novos materiais com gradação funcional, podem ser
tratados consistentemente, pelo menos para problemas de
potencial. Alguns
exemplos numéricos simples são apresentados como
ilustração dos
desenvolvimentos teóricos. / [en] The hybrid finite element method, proposed by Pian on the
basis of the
Hellinger-Reissner potential, has proved itself a
conceptual breakthrough among
the discretization formulations, and has been extensively
explored both
academically and in commercial codes also taking into
account an independent
series of more recent developments called Trefftz methods.
The hybrid boundary
element method is a successful generalization of Pian´s
original formulation, in
which Green´s functions are taken as interpolation
functions in the domain, thus
enabling the robust and accurate modeling of arbitrarily
shaped bodies submitted
to several types of actions. More recently, a proposition
by Przemieniecki - for
the generalized free vibration analysis of truss and beam
elements - was
incorporated into the hybrid boundary element formulation
and extended to the
analysis of time-dependent problems by making use of an
advanced mode
superposition procedure that takes into account general
initial conditions as well
as general body actions, besides the inertial effect. The
present contribution aims
to bring to finite elements the conceptual improvements
obtained in the frame of
the hybrid boundary element method. A large family of
hybrid, macro finite
elements is introduced for the unified treatment of 2D and
3D, static and transient
problems of elasticity and potential on the basis of
nonsingular fundamental
solutions. It is also shown that nonhomogeneous materials,
as the novel
functionally graded materials, may be dealt with
consistently, at least for potential
problems. Some simple numerical examples are shown to
illustrate the
theoretical developments.
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Development of Novel Green’s Functions and Their Applications to Multiphase and Multilayered StructuresHan, Feng 05 October 2006 (has links)
No description available.
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Strategies for the Characterization and Virtual Testing of SLM 316L Stainless SteelHendrickson, Michael Paul 02 August 2023 (has links)
The selective laser melting (SLM) process allows for the control of unique part form and function characteristics not achievable with conventional manufacturing methods and has thus gained interest in several industries such as the aerospace and biomedical fields. The fabrication processing parameters selected to manufacture a given part influence the created material microstructure and the final mechanical performance of the part. Understanding the process-structure and structure-performance relationships is very important for the design and quality assurance of SLM parts. Image based analysis methods are commonly used to characterize material microstructures, but are very time consuming, traditionally requiring manual segmentation of imaged features. Two Python-based image analysis tools are developed here to automate the instance segmentation of manufacturing defects and subgranular cell features commonly found in SLM 316L stainless steel (SS) for quantitative analysis. A custom trained mask region-based convolution neural network (Mask R-CNN) model is used to segment cell features from scanning electron microscopy (SEM) images with an instance segmentation accuracy nearly identical to that of a human researcher, but about four orders of magnitude faster. The defect segmentation tool uses techniques from the OpenCV Python library to identify and segment defect instances from optical images. A melt pool structure generation tool is also developed to create custom melt-pool geometries based on a few user inputs with the ability to create functionally graded structures for use in a virtual testing framework. This tool allows for the study of complex melt-pool geometries and graded structures commonly seen in SLM parts and is applied to three finite element analyses to investigate the effects of different melt-pool geometries on part stress concentrations. / Master of Science / Recent advancements in additive manufacturing (AM) processes like the selective laser melting (SLM) process are revolutionizing the way many products are manufactured. The geometric form and material microstructure of SLM parts can be controlled by manufacturing settings, referred to as fabrication processing parameters, in ways not previously possible via conventional manufacturing techniques such as machining and casting. The improved geometric control of SLM parts has enabled more complex part geometries as well as significant manufacturing cost savings for some parts. With improved control over the material microstructure, the mechanical performance of SLM parts can be finely tailored and optimized for a particular application. Complex functionally graded materials (FGM) can also easily be created with the SLM process by varying the fabrication processing parameters spatially within the manufactured part to improve mechanical performance for a desired application. The added control offered by the SLM process has created a need for understanding how changes in the fabrication processing parameters affect the material structure, and in turn, how the produced structure affects the mechanical properties of the part. This study presents three different tools developed for the automated characterization of SLM 316L stainless steel (SS) material structures and the generation of realistic material structures for numerical simulation of mechanical performance. A defect content tool is presented to automatically identify and create binary segmentations of defects in SLM parts, consisting of small air pockets within the volume of the parts, from digital optical images. A machine learning based instance segmentation tool is also trained on a custom data set and used to measure the size of nanoscale cell features unique to 316L (SS) and some other metal alloys processed with SLM from scanning electron microscopy (SEM) images. Both these tools automate the laborious process of segmenting individual objects of interest from hundreds or thousands of images and are shown to have an accuracy very close to that of manually produced results from a human. The results are also used to analyze three different samples produced with different fabrication processing parameters which showed similar process-structure relationships with other studies. The SLM structure generation tool is developed to create melt pool structures similar to those seen in SLM parts from the successive melting and solidification of material from the laser scanning path. This structural feature is unique to AM processes such as SLM, and the example test cases investigated in this study shows that changes in the melt pool structure geometry have a measurable effect, slightly above 10% difference, on the stress and strain response of the material when a tensile load is applied. The melt pool structure generation tool can create complex geometries capable of varying spatially to create FGMs from a few user inputs, and when applied to existing simulation methods for SLM parts, offers improved estimates for the mechanical response of SLM parts.
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Schalentragwerke mit funktionaler GradierungIllguth, Sandy, Lowke, Dirk, Kränkel, Thomas, Gehlen, Christoph 21 July 2022 (has links)
Betone für schlanke Schalentragwerke weisen zur Sicherstellung ausreichender Zugfestigkeiten oft einen hohen Stahlfasergehalt auf. Dies ist mit hohen ökologischen und monetären Kosten verbunden. Das Ziel war es daher, die Voraussetzungen für die Herstellung effizienter Schalentragwerke aus funktional fasergradierten Betonfertigteilen zu schaffen. / Concrete for slender load-bearing shell structures often has a high steel fibre content to ensure sufficient tensile strength. This is associated with high ecological and financial costs. Thus, the aim of this project was to create the prerequisites for the production of efficient shell structures made of functional fibre-graded precast concrete elements.
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