On material-convective elasto-plasticity

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

On the Multiplicative Logarithmic Strain Space Formulation

A new constitutive approach to finite-deformation formulations of elasto-plasticity (with isotropic thermal expansion) is presented, which is well-suited to a broad range of metals used for industrial applications. The constitutive equations are formulated within the logarithmic strain space. The coupling of elasticity, plasticity and thermal expansion is based on a multiplicative approach of commutative-symmetric stretch tensor products with symmetrizing rotation tensors in the middle of two symmetric stretch tensors. It is essential for finite-deformation formulations to refer to an appropriate reference configuration K0 in order to model material orthotropy correctly (and not to mix up material / physical anisotropy with deformation-induced / geometrical anisotropy). Furthermore, it is essential to define proper stretch and strain tensors which are geometrical interpretable, i.e. which only depend on a current  K and a reference K0 configuration (and not on the geometrical deformation path between these configurations). Therefore, all stretch and strain tensors are defined with respect to the same reference configuration K0, the total stretches and strains as well as the partial ones: the elastic, plastic and thermal stretches and strains. And these reference configurations should be the appropriate ones, where—in the case of fiber-reinforced (metal) bodies—the fibers are placed orthogonal to each other or where Walter Noll’s symmetry group considerations characterize the physical nature of materials with their most specificity as: orthotropic, transversal isotropic or fully isotropic

Teststrategien im virtuellen Deutschunterricht

Empirische Studien belegen, dass in virtuellen Kursen häufiger unlautere Mittel eingesetzt werden als im Präsenzunterricht. Dieser Artikel zeigt anhand zweier Fallbeispiel aus dem universitären virtuellen DaF-Unterricht verschiedene Möglichkeiten, die Integrität eines Kurses ohne eine Vielzahl an intrusiven technischen Mitteln zu gewährleisten. Während eine logische Reihung von formativen und summativen Tests den direkten Vergleich studentischer Leistungen erlaubt, kann durch die Kombination asynchroner und synchroner Unterrichtselemente eine Datenbank erstellt werden, welche als Grundlage zur Bewertung von Tests dient.Digitalisierung, Evaluation, online lernen, Teststrategien, virtuelle LehreEmpirical studies show a higher frequency of cheating in virtual courses than in face-to-face classes. This article uses two case studies of university-level virtual German language classes to show less-intrusive, non-technical methods that still ensure the course integrity. Whereas sequencing formative and summative tests appropriately allows the direct comparison of student performance, a combination of asynchronous and synchronous assignments can be used to create a database for the evaluation of test results.Digitalization, evaluation, online learning, testing strategies, virtual teachin

Emerging from the Niche: DEFA’s Afterlife in Unified Germany

The cinema of the GDR has seen a steep rise in popularity since German unification. DEFA is now a popular “brand,” with its films being omnipresent on television, in movie theaters, and on DVD, Blu-ray, and online streaming video. Reasons for this success are located in the current infrastructure of DEFA cinema. Since 1999, DEFA-Stiftung, Progress Filmverleih, and Icestorm Entertainment have (re-)introduced the GDR’s cinematic legacy to German culture, where audiences embrace the new media as reminders of a bygone time.This is an author's peer-reviewed final manuscript, as accepted by the publisher. The article is copyrighted by the Board of Regents of the University of Wisconsin System and published by the University of Wisconsin Press. It can be found at: http://mon.uwpress.org/.Keywords: East Germany, Marketing, German cinem

Inspiring and Educating GDR Women: Iris Gusner, Feminism, and the Film Kaskade Rückwärts

Directing feature films in the GDR was largely a male-dominated profession. One of the few female directors was Iris Gusner, whose films explored issues working GDR women faced in their everyday lives. A close reading of her 1984 feature film Kaskade Rückwärts, in particular the focus on sound and on camera angles, exemplifies clandestine strategies Gusner used to create a feminist film. Gusner reveals the hypocrisy prevalent in GDR society pertaining to achieving gender equality as she sets up her heroine embarking on a quest for love in a patriarchal GDR. A narrative that initially appears to confirm patriarchal structures gradually turns into a cinematic feminist manifesto that successfully challenges GDR gender ideology. As a result Kaskade offered female GDR viewers a motivating experience and simultaneously challenged the male-dominated GDR film industry.This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the University of Nebraska Press and can be found at: http://www.nebraskapress.unl.edu/product/Women-in-German-Yearbook,673912.aspxKeywords: East Germany, Women directors, Feminism, DEFA, Iris Gusner, Fil

“Das ist die Mauer, die quer durchgeht. Dahinter liegt die Stadt und das Glück: DEFA Directors and their Criticism of the Berlin Wall”

This article examines the strategies used by directors of the East German film monopoly Deutsche Film-Aktiengesellschaft (DEFA) to voice their disapproval of the Berlin Wall.1 My aim is to show how it was possible, despite universal censorship in East Germany, to create films that addressed the wall as an inhumane means to imprison the East German people. Although many DEFA films adhered to socialist law and reiterated the official doctrine of the «antifascist protection rampart» on the silver screen, an analysis of three DEFA films will demonstrate how the representation of human crisis was used as a means to criticize the wall.2 The films Das Kleid (Konrad Petzold, 1961), Der geteilte Himmel (Konrad Wolf, 1964), and Die Architekten (Peter Kahane, 1990) address walls in a variety of functions and appearances as representations, symbols, and metaphors of the barrier between East and West Germany.Keywords: Cinema, Berlin Wall, Director, DEFA, East German

Inspiring and Educating GDR Women: Iris Gusner, Feminism, and the Film Kaskade Rückwärts

Directing feature films in the GDR was largely a male-dominated profession. One of the few female directors was Iris Gusner, whose films explored issues working GDR women faced in their everyday lives. A close reading of her 1984 feature film Kaskade Rückwärts, in particular the focus on sound and on camera angles, exemplifies clandestine strategies Gusner used to create a feminist film. Gusner reveals the hypocrisy prevalent in GDR society pertaining to achieving gender equality as she sets up her heroine embarking on a quest for love in a patriarchal GDR. A narrative that initially appears to confirm patriarchal structures gradually turns into a cinematic feminist manifesto that successfully challenges GDR gender ideology. As a result Kaskade offered female GDR viewers a motivating experience and simultaneously challenged the male-dominated GDR film industry.This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the University of Nebraska Press and can be found at: http://www.nebraskapress.unl.edu/product/Women-in-German-Yearbook,673912.aspx,This article may also be accessed through the Project MUSE journal site which is located at: http://muse.jhu.edu/journals/women_in_german_yearbook/Keywords: DEFA, Film, East Germany, Feminism, Iris Gusner, Women director

Localizing the Milljöh in Gerhard Lamprecht’s Irgendwo in Berlin (1946)

Paper presented at the 2013 Annual Conference of the German Studies Association.Scholars studying Gerhard Lamprecht’s Irgendwo in Berlin (Soviet Occupied Zone, 1946) usually approach it within the context of a non-genre, the Trümmerfilm. Set in the rubble of Berlin Lamprecht’s film also invokes a number of traditions harking back to Weimar cinema of the 1920s, and thus invites a re-reading that references Lamprecht’s pre-1933 cinematic oeuvre. In particular, the Milljöh-Filme Lamprecht shot together with the graphic artist Heinrich Zille allow us to link Irgendwo in Berlin to the tradition of proletarian Berlin-films. In my paper, I read Irgendwo in Berlin as continuation and combination of such a tradition. By referencing the different policies and restrictions imposed by each occupying force for film production in their sector I suggest that Lamprecht foregrounded the rubble to appease the Soviet Military Administration and get permission to shoot this film. Yet, once we look beyond the rubble Irgendwo in Berlin reveals the typical proletarian stories set in Berlin’s “Zille-Milieu” which Lamprecht’s filmmaking had become known for in Weimar: stories of unemployment and hunger, disillusionment and frustration, petty crime and the presence of death. Much like in these Milljöh-Filme Lamprecht also leads the audience to original locations as we venture into Berlin’s tenement buildings, peer into basements and courtyards, and experience the everyday life of proletarians. The living conditions and lack of work reiterate the problems of the Weimar proletarian film, and like its predecessors Irgendwo in Berlin offers a glimmer of hope that progress and an improvement of the living conditions will become possible by solidarity. Looking at Irgendwo in Berlin as a Milljöh-Film thus challenges the notion of at least this Trümmerfilm as a film of a “Zero Hour,” and instead proposes a much closer connection of DEFA filmmaking to the cinematic traditions of before 1933

GDR Cinema as Commodity: Marketing DEFA Films since Unification

For more than a decade, feature films produced by the GDR film company DEFA have been popular items in Germany. I analyze these films as commodities, arguing that this success by DEFA cinema needs to be read in conjunction with clever marketing strategies employed by the nonprofit foundation DEFA-Stiftung and the commercial home video distributor Icestorm Entertainment. Tracing some of these strategies, I show how DEFA feature films have become identifying markers that attest to a new eastern German regionalism and the reconsideration of the GDR past as part of Germany’s cultural history.This is the publisher’s final pdf. The published article is copyrighted by the Johns Hopkins University Press and can be found at: http://www.press.jhu.edu/journals/german_studies_review/.Keywords: Cinema, Popular culture, DEFA, Nostalgia, East Germany, MarketingKeywords: Cinema, Popular culture, DEFA, Nostalgia, East Germany, Marketin

Analytical assessment of the load carrying capacity of axially loaded wooden reinforced tubes

As a natural resource, an efficient use of wood should be also a requirement for structural timber design, but the usual structural solid sections do not achieve the required optimal behaviour. The performance of the structural elements (serviceability and strength) depends not only on the material properties, but mainly on the moment of inertia of the cross section. The Timber Construction Institute of Technische Universitát Dresden has developed a process for the manufacture of structural wood profiles. The resulting profiles combine economy, an efficient use of the material and optimal structural performance. They are externally reinforced with composite fibres, which improve the mechanical characteristics of the wood and protect it from weathering. The available experimental tests to axial loading show the outstanding properties of this new technology. Herein, the preliminary model developed to obtain the axial strength of longitudinally compressed tubes is presented. Two different analytical algorithms are discussed and applied. The model adequately predicts the axial strength of fibre reinforced wood profiles. The analytical results are within an error less than 10% to the available experimental results, with a mean error ratio less than 3%