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Nonlinear-Elastic Orthotropic Material Modeling of an Epoxy-Based Polymer for Predicting the Material Behavior of Transversely Loaded Fiber-Reinforced Composites

Nonlinear-Elastic Orthotropic Material Modeling of an Epoxy-Based Polymer for Predicting the Material Behavior of Transversely Loaded Fiber-Reinforced Composites

Received: 6 April 2020; Accepted: 30 April 2020; Published: 2 May 2020    Abstract: Micromechanical analyses of transversely loaded fiber-reinforced composites are conducted to gain a better understanding of the damage behavior and to predict the composite behavior from known parameters of the fibers and the matrix. Currently, purely elastic material models for the epoxy-based polymeric matrix do not capture the nonlinearity and the tension/compression-asymmetry of the resin’s material behavior. In the present contribution, a purely elastic material model is presented that captures these effects. To this end, a nonlinear-elastic orthotropic material modeling is proposed. Using this matrix material model, finite element-based simulations are performed to predict the composite behavior under transverse tension, transverse compression and shear. Therefore, the composite’s cross-section is modeled by a representative volume element. To evaluate the matrix modeling approach, the simulation results are compared to experimental data and the prediction error is computed. Furthermore, the accuracy of the prediction is compared to that of selected literature models. Compared to both experimental and literature data, the proposed modeling approach gives a good prediction of the composite behavior under matrix-dominated load cases.
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Generalized delaunay partitions and composite material modeling

Generalized delaunay partitions and composite material modeling

that are projected onto the same elements of Q. In a similar manner Voronoi partitions with respect to a system of closed convex sets I = {I1 , . . . , I N } ⊆ P(R n ) are introduced. The convex sets I ∈ I are denoted as inclusions according to composite material modeling and in contrast to the literature where there sets are typically called generators. We note that the inclusions are not assumed to be pairwise disjoint. They might touch each other. However, general intersections are excluded, i.e. we assume that the intersection of any two inclusions is of lower dimension:

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A New Approach in Material Modeling Towards Shear Cutting of Carbon Fiber Reinforced Plastics

A New Approach in Material Modeling Towards Shear Cutting of Carbon Fiber Reinforced Plastics

In this paper, a new approach in material modeling related to shear cutting of carbon fiber reinforced plastics (CFRP) is introduced. The aim is to formulate a phenomenological model accounting for the inner (micromechan- ical) processes which influence the cutting behavior and the quality of the cutting surface. This is required to make shear cutting of CFRP suitable for mass production like car manufacturing in terms of reduction of processing costs.

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Variational material modeling of the transformation induced plasticity in polycrystalline steel

Variational material modeling of the transformation induced plasticity in polycrystalline steel

The eponymous effect of transformation induced plasticity (TRIP) in steel describes a simultaneous phase transformation and plastic deformation. The literature related to the particular modeling of the individual microstructural effects - the plastic deforma- tion and the phase transformation - is huge. A good overview of plasticity is given in Lubliner (2008). Plasticity models based on variational concepts are exemplary given in Han et al. (1995); Lubliner (1984); Mühlhaus and Alfantis (1991) and for the case of crystal plasticity in, e.g., Svendsen and Bargmann (2010); Hackl et al. (2014); Conti et al. (2009). To mention but a few modeling concepts for martensitic phase transformations, we would like to refer to Govindjee and Hall (2000); Auricchio and Petrini (2004); Govindjee and Miehe (2001); Turteltaub and Suiker (2006b); Babaei et al. (2019). In the past, also, a lot of works have been related to the modeling of the special material behavior of TRIP-steels. Besides earlier works which couple the martensitic phase transformation with plastic deformation by ,e.g., Greenwood and Johnson (1965), Leblond et al. (1986), Leblond et al. (1989), Fischer (1990). The model of Levitas (1998) also examined the martensitic transformation at interfaces and thus at discontinuities of the displacement field in an inelastic material. The model by Olson and Cohen (1975) is the basis for the later studies Iwamoto and Tsuta (2000, 2002): the martensitic transformation is driven by a shear band intersection and a stochastic ansatz is used for the formation of a nucleus. The extension Iwamoto and Tsuta (2000) accounts for a dependence on the austenitic grain size and furthermore, a high fracture toughness is examined in Iwamoto and Tsuta (2002). A study on the change of material properties related to hardening due to the TRIP effect based on Iwamoto and Tsuta (2000) is given in Dan et al. (2008). Another promising approach based on stochastic considerations is presented in Ostwald et al. (2011) for one-dimensional problems; its 3D-extension and finite-element-implementation is given in Ostwald et al. (2012). The models are based on the probabilistic approach for phase transformations by Govindjee and Hall (2000) which may not only be applied for modeling the TRIP effect, but also for shape memory alloys. Also the work Bartel et al. (2011) of the same group presents an energy relaxation based approach, which uses a classical J 2 -vonMises-type plasticity. In this work a special focus lies on the inheritance of the plastic strain. Another energetic
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Material Modeling and Microstructural Optimization of Dielectric Elastomer Actuators

Material Modeling and Microstructural Optimization of Dielectric Elastomer Actuators

The modeling and 3D numerical implementation of dielectric elastomer actuators are discussed in this work. The electromechanical coupling for the actuator is realized via the Maxwell stress in the mechanical balance. In this nonlinear numerical problem the consistent tangent matrix, which is used for the Newton iterations, is described in detail. The operational curve of a homogeneous capacitor structure is compared to analytical solutions by imple- menting the Neo-Hooke and the Yeoh material model in the numerical simulations respectively. In this simulations the instability aspects of this type of structure is discussed. Furthermore the optimization of the operational curve is analyzed for both material models through the consideration of inclusion materials in the elastomer structure. Piezoceramic and a soft material inclusions with a fiber and a spherical geometry are considered. The results show the capability of improving the operational curves of the actuator with these inhomogeneities.
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Material Modeling of Microstructured Solids — Theory, Numeric and Applications —

Material Modeling of Microstructured Solids — Theory, Numeric and Applications —

Closely related to observer invariance is the expectation that the energy of a deformed elastic body remains unchanged when a rigid-body motion is superposed on an existing deformation. This requirement leads to the principle of material-frame indiffer- ence. Material-frame indifference is a somewhat questionable requirement because in some — rare — cases it might be physical meaningful that material properties change with, e.g., superposed fast rotations. The validity of this principle, its physical interpre- tation and the fundamental differences of the principles of objectivity and of material- frame indifference are subject of extensive discussions in theoretical literature, see, e.g., [33, 34, 235]. We consider here only common, acceleration-independent solid materials. In this case both, the agreement among observers about the perceived material response, i.e., objectivity, and the invariance of material response to superposed rigid body mo- tions, i.e., material-frame indifference, coincide de facto. For more theoretical details we refer to the cited literature.
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Enhancing Material Nature

Enhancing Material Nature

The notion that we might recruit nature to surpass nature is not new. It has a long history, at least in alchemy and other magical sciences, in romantic philosophy of nature (Naturphilosophie), but also in theories of self-organization and, not least, in biomimetics or bionics. If there is anything new about it in the context of nanotechnologies, then it is its innocuous appearance and the way in which it is taken for granted. In fact, it assumes a kind of spectacular prominence only in the debates about so-called transhumanism and its goal of technologically enhancing human nature, which is to be enabled, somehow, by nanotechnologies and their convergence with other emerging technologies. In contrast, the idea of mobilizing nature to go beyond nature goes just about unnoticed where it proves to be fundamental, namely with regard to the project of technologically enhancing or surpassing material nature. This basic idea therefore needs to be brought to light before it can be properly contextualized historically and appreciated philosophically.
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Material utilization of organic waste

Material utilization of organic waste

Abstract Each year, 1.3 billion tons of food waste is generated globally. This waste traces back to industrial and agricultural producers, bakeries, restaurants, and households. Further- more, lignocellulosic materials, including grass clippings, leaves, bushes, shrubs, and woods, appear in large amounts. Depending on the region, organic waste is either composted, burned directly, or converted into biogas. All of the options set aside the fact that organic residues are valuable resources containing carbohydrates, lipids, proteins, and phosphorus. Firstly, it is clear that avoidance of organic residues is imperative. However, the residues that accumulate nonetheless should be utilized by material means before energy production is targeted. This review presents different processes for the microbial utilization of organic residues towards compounds that are of great importance for the bioeconomy. The focus thereby is on the challenges coming along with downstream processing when the utilization of organic residues is carried out decentralized. Furthermore, a future process for producing lactic acid from organic residues is sketched.
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Perception of Material Kinematics

Perception of Material Kinematics

Banks, 2002, Knill 2007), where the sensory cues may be in conflict with one another and/or the prior belief. While we do not aim to model our results formally, we still believe that this analogy is useful in interpreting our findings. We will first focus on the rating differences that we found in the Expected and Surprising conditions. Here, objects that physically deformed, i.e. Wrinkled, splashed, etc, in the same way were not rated the same way. In fact, in many cases, ratings were ‘pulled’ towards the expected material property, not the signaled one. For example, a wrinkling spoon or teacup was rated harder than any of the wrinkling cloths. Here, prior knowledge about spoons and teacups being hard seems to have led to increased ratings of hardness compared to their soft curtain counterparts, despite all of these objects wrinkling. This outcome would be best explained by a so-called down- weighing of the cues (Knill, 2007) to hardness, which suggests that the visual system entertains multiple priors (strong and weaker ones) about the state of the world, and that, depending on the sensory input, it adjusts the weights of these priors. This implies that in a cue-conflict situation, the unlikely interpretation of the input does not simply get vetoed down (Landy et al. 1995), but that instead it would factor into the final percept – just as we observed it in our results.
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Greenpeace - Material zum internationalen Klimaschutz

Greenpeace - Material zum internationalen Klimaschutz

Das Material ist für Schüler*innen ab Klasse 7 entwickelt und knüpft an die Bildungspläne der Länder an. Es besteht aus vier Themenblöcken mit Unterrichtsimpulsen und Arbeitsblättern. Die Unterrichtsimpulse geben Ihnen methodische und inhaltli- che Anregungen. Sie bauen aufeinander auf, können aber auch unabhängig voneinander genutzt werden und bieten Raum für Ihre individuelle Ausgestaltung. Die Arbeitsblätter können Sie direkt im Unterricht einsetzen; Hinweise zur Vor- und Nach- bereitung sowie Lösungshinweise finden Sie in den Unterrichts- impulsen. Erweiterte Aufgabenstellungen für eine vertiefte Auseinandersetzung sowie hilfreiche Links sind mit Symbolen gekennzeichnet.
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Material- und Produktrecycling – am Beispiel von Plattenbauten

Material- und Produktrecycling – am Beispiel von Plattenbauten

Maßnahme Vorhaben / Standort Baujahr / Planer Spender- gebäude Transport- entfernung [km] Wieder-/ Weiter-. verwendung Kenndaten Kosten[r]

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Material zur GFS Fibonacci-Folge

Material zur GFS Fibonacci-Folge

Er veröffentlichte verschiedene Bücher, von denen einige noch heute in Abschriften erhalten sind. Mit seinem Namen verbinden sich besondere Leistungen in der Arithmetik und Algebra [r]

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Material zur GFS Fibonacci-Folge

Material zur GFS Fibonacci-Folge

Fig.. Diese *ar jedoch stltort iiber I00 Jalre t,orlrcr bekannt, ohne dass Bnuer dizs u'rtsste. Sohn des Bonacci) genannt wurde, war ein Kaufmann, der auf seinen Reisen d[r]

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Material science examination on pineapple fruit puree and raw material

Material science examination on pineapple fruit puree and raw material

The pectin molecule is quite easily degraded. Although pectin, in contrast to other gums, is fairly stable under acid conditions, its chemical structure makes it prone to breakdown under less acid conditions, at a pH of 5 or above, especially at higher temperatures. Because the reaction can occur wherever there is an esterifies acid group in the molecular chain, a small amount of degradation can give a large loss in viscosity, gelling power and other functional properties. The rate of degradation is less with low methoxyl pectins, and virtually absent in pectic acid, the fully de-esterifies material, and its salts. Hence, only pectic acid or pectins of very low degrees of esterification can be used in neutral products, especially those which are to be heat processed. (Imeson, 1994) Thermal degradation was generally used to pectin. Godeck, Kunzek & Kabbert (2001) found difference in thermal degradation behavior in dependence on the degree of methoxylation (DM) of pectin component.
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Material and Methods 

Material and Methods 

Anti­ nociceptive activity was expressed as the reduction of the number of abdominal contractions between control animals and mice pretreated with morusin and standard dru[r]

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Asian material culture

Asian material culture

with a beautiful object. For the visible colour-textures of all objects, like Long Skirt, are necessarily emplaced in space and time. They comprise but an anchor for our own ‘period eye’ (Baxandall 1972) 3 and the multiple kinds of relations, actions, thoughts and sensations that occur for each observer, bodily, as well as in the mind. Long Skirt, for example, forms but a single set of material fragments at Langde within a broader contextual realm, where the visitor’s own cultural ‘make-up’ couples the projected exoticism of its wearers and imagined creators, the quaintness of the wooden village architecture, sounds of jangling pressed silver fringing and village music and the taste of food and wine. Together with the ‘pristine’ beauty of the outlying rural surrounds, these fragments cause their sensory efficacy to be amplified. The model of the arbitrary linguistic sign may help to speculate upon this process by enabling us to locate meanings drawn by eye from colour as text, discursively, in time. But as we rarely, if ever, perceive the world through one sense alone, particularly in the case of fascination with Miao costume at Langde, it is necessary to consider a more embodied model of apprehension that recognises the unified nature of the human sensorium (Pinney 2002) to go on.
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Regionale Material- und Energieflußrechnungen

Regionale Material- und Energieflußrechnungen

§ In der aktivitätsbezogenen Rechnung wird das Aufkommen und die Verwendung von Material und Energie dargestellt, die von den Aktivitäten der 58 Produktionsbereiche der inländischen Wirtschaft sowie der Haushalte ausgehen. Unter einem Produktionsbereich ist dabei die Gesamt- heit aller wirtschaftlichen Aktivitäten, die ausschließlich und vollständig die Güter einer Güter- gruppe erzeugen, zu verstehen. Durch die Verwendung der Gliederung nach homogenen Produk- tionsbereichen können die Daten zu umweltrelevanten Material- und Energieströmen sowie zu Umweltbelastungen direkt in Beziehung zu ökonomischen Kennziffern aus der Volkswirtschaft- lichen Gesamtrechnung gesetzt werden. Produktionsbereiche stellen somit das Bindeglied zwischen Wirtschafts- und Umweltdaten dar.
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Index of /Material/Pruefungen

Index of /Material/Pruefungen

Das Prüfungszimmer wird jeweils im Stundenplan eingetragen.. Klasse 1.[r]

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On material-convective elasto-plasticity

On material-convective elasto-plasticity

Abstract: A material-convective continuum formulation is presented which differs significantly from the finite elasto-plasticity descriptions of general-purpose finite element simulation tools like Dyna3D, Abaqus, Marc, etc. The material-convective continuum formulation offers physical significance in particular with respect to the geometrical interpretation of the (plastic) deformation tensors—in contrast to the so-called Updated Lagrangian Formulation of general-purpose finite element simulation tools which is unphysical due to its inaccurate (directional non-convective) integration of the (plastic) deformation increments: this inaccurately integrated (plastic) deformation does not obey the geometrical interpretation of proper (plastic) deformation tensors and may even lead to a violation of the first fundamental law of thermodynamics, the conservation of energy. The material-convective time integrals are the reverse of the material-convective time derivatives, and the only material-convective time derivative of a symmetric second-order Eulerian tensor is its Green-Naghdi rate which is rotationally and translationally convected with the material.
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Emission Modeling

Emission Modeling

In a similar study, Song et al. (2012) couple VISSIM (Verkehr In St¨adten – SImulationsModell) with the emission modeling tool MOVES. They find that the VISSIM (Verkehr In St¨adten – SImulationsModell)-simulated, vehicle-specific power distribution for passenger cars deviates sig- nificantly from the observed distribution, meaning that the estimated emissions also contain significant errors. Here again, the proposed model cannot be used for large-scale scenarios. Additionally, it seems questionable whether such detailed modeling will prove to be superior to less detailed models as the EMT.
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