@inproceedings{22021,
abstract = {{Additive production techniques have the advantage of manufacturing parts without needing a forming tool. One of the most used additive manufacturing processes is "Fused Deposition Modeling" (FDM) which allows the production of prototypes and end-use parts. Due to the manufacture layer by layer, also complex part geometries can be created in one working step. Furthermore, lightweight parts with specific inner core structures can be manufactured in order to achieve good weightrelated strength properties. In this paper the mechanical behavior of lightweight parts manufactured with the 3D production system Fortus 400mc from Stratasys and the material Polyetherimide (PEI) with the trade name Ultem*9085 is analyzed. The test specimens were built up with different inner structures and building directions. Therefore, test specimens with known lightweight core geometries (e.g. corrugated and honeycomb cores) were designed. A four-point bending test was conducted to analyze the strength properties as well as the weight-related strength properties. Additionally the influence of the structure width, the structure wall thickness and the top layer thickness was analyzed using a honeycomb structure.}},
author = {{Bagsik, A. and Josupeit, S. and Schöppner, Volker and Klemp, E.}},
booktitle = {{29th International Conference of the Polymer Processing Society}},
pages = {{696--701}},
publisher = {{American Institute of Physics }},
title = {{{Mechanical Analysis of Lightweight Constructions manufactured with Fused Deposition Modeling}}},
doi = {{10.1063/1.4873874}},
volume = {{29}},
year = {{2014}},
}
@article{15965,
abstract = {{Abstract}},
author = {{Leuders, Stefan and Lieneke, Tobias and Lammers, Stefan and Tröster, Thomas and Niendorf, Thomas}},
issn = {{0884-2914}},
journal = {{Journal of Materials Research}},
pages = {{1911--1919}},
title = {{{On the fatigue properties of metals manufactured by selective laser melting – The role of ductility}}},
doi = {{10.1557/jmr.2014.157}},
year = {{2014}},
}
@article{24708,
author = {{Widany, Kai-Uwe and Mahnken, Rolf}},
issn = {{1617-7061}},
journal = {{PAMM}},
pages = {{273--274}},
title = {{{Approximation of the dual problem for error estimation in inelastic problems}}},
doi = {{10.1002/pamm.201410124}},
year = {{2014}},
}
@article{24702,
author = {{Cheng, Chun and Mahnken, Rolf and Uhlmann, Eckart and Ivanov, Ivan Mitkov}},
issn = {{1617-7061}},
journal = {{PAMM}},
pages = {{419--420}},
title = {{{Macroscopic and mesoscopic modeling based on the concept of generalized stresses for cutting simulation}}},
doi = {{10.1002/pamm.201410197}},
year = {{2014}},
}
@article{24701,
author = {{Dammann, Christian and Mahnken, Rolf}},
issn = {{1617-7061}},
journal = {{PAMM}},
pages = {{387--388}},
title = {{{A macroscopic consitutive model on induced anisotropy for polymers with weighting functions}}},
doi = {{10.1002/pamm.201410181}},
year = {{2014}},
}
@article{24707,
abstract = {{Abstract
The alignment of polymer chains is a well known microstructural evolution effect due to straining of polymers. This has a drastic influence on the macroscopic properties of the initially isotropic material. In this work, cold forming is performed at room temperature on a tensile testing machine. Polycarbonate films are examined in two loading phases. In the first phase, the specimen is loaded to induce anisotropy, and in the second, it is re-loaded, while the material direction is varied. The investigations are supported by an optical measurement system to gain knowledge about the inhomogeneous material behavior in the initial loading phase and about the anisotropic homogeneous behavior during the re-loading phase. Two dimensional strain contours are obtained from the test data. Additionally, we propose a method for approximation of the macroscopic true stress and compare the results with a common approach based on volume consistency. In the future, the test data will set a basis for parameter identification of constitutive equations taking into account a combination of inhomogenous and homogenous material behavior, exhibiting strain induced anisotropy.}},
author = {{Dammann, C. and Caylak, Ismail and Mahnken, Rolf}},
issn = {{2195-8602}},
journal = {{International Polymer Processing}},
pages = {{260--271}},
title = {{{Experimental Investigation of PC-Films Using Optical Measurements}}},
doi = {{10.3139/217.2848}},
year = {{2014}},
}
@article{24700,
author = {{Mahnken, Rolf and Schneidt, A. and Antretter, T. and Ehlenbröker, U. and Wolff, M.}},
issn = {{0020-7683}},
journal = {{International Journal of Solids and Structures}},
pages = {{156--171}},
title = {{{Multi-scale modeling of bainitic phase transformation in multi-variant polycrystalline low alloy steels}}},
doi = {{10.1016/j.ijsolstr.2014.10.021}},
year = {{2014}},
}
@inproceedings{24706,
author = {{Dammann, C. and Mahnken, Rolf}},
title = {{{On the simulation of strain induced anisotropy for polymers}}},
doi = {{10.1063/1.4873891}},
year = {{2014}},
}
@article{24703,
author = {{Mahnken, Rolf and Nörenberg, Nicole}},
issn = {{1617-7061}},
journal = {{PAMM}},
pages = {{427--428}},
title = {{{Parameter identification for rubber materials with artificial higher dimensional data}}},
doi = {{10.1002/pamm.201410201}},
year = {{2014}},
}
@article{24704,
author = {{Ehlenbröker, Ulrich and Mahnken, Rolf}},
issn = {{1617-7061}},
journal = {{PAMM}},
pages = {{381--382}},
title = {{{Bainitic variant evolution in a low-alloyed steel including numerical aspects}}},
doi = {{10.1002/pamm.201410178}},
year = {{2014}},
}
@article{19116,
author = {{Caylak, Ismail and Mahnken, Rolf}},
issn = {{0045-7949}},
journal = {{Computers & Structures}},
pages = {{172--182}},
title = {{{Stabilized mixed triangular elements with area bubble functions at small and large deformations}}},
doi = {{10.1016/j.compstruc.2014.01.006}},
year = {{2014}},
}
@inproceedings{16098,
author = {{Moritzer, Elmar and Budde, C. and Tröster, Thomas and Pöhler, Simon}},
isbn = {{978-3-88355-402-0}},
location = {{Stade}},
pages = {{101--108}},
title = {{{Study of the Bond Strength of a Combination Consisting of Composite Sheet and Short-Fiber Thermoplastic}}},
year = {{2014}},
}
@article{16125,
author = {{Moritzer, Elmar and Budde, C. and Tröster, Thomas and Pöhler, Simon}},
journal = {{Joining Plastics }},
number = {{2}},
pages = {{100--105}},
title = {{{Parametereinfluss auf die Verbundfestigkeit einer Organoblech-Kurzfaserthermoplast-Werkstoffkombination}}},
volume = {{8}},
year = {{2014}},
}
@inproceedings{16130,
author = {{Weiß Borkowski, Nathalie and Marten, Thorsten and Tröster, Thomas}},
booktitle = {{Fortschritte in der Werkstoffprüfung für Forschung und Praxis, Tagungsband Werkstoffprüfung }},
editor = {{Grellmann, Wolfgang and Frenz, Holger}},
isbn = {{9783981451689}},
location = {{Berlin}},
publisher = {{DVM}},
title = {{{Mehrachsige Werkstoffprüfung bei hoher Dehnrate im Hochgeschwindigkeits-Tiefungsversuch}}},
year = {{2014}},
}
@article{28381,
abstract = {{With self-reinforced thermoplastics, it is possible to produce composite systems that, unlike traditional fiber composite materials, do not contain any foreign fibers for reinforcement. Instead, thermoplastic fibers or tapes, for example made of PP or PE, are used in an identical matrix. This opens up a high potential for lightweight construction and, at the same time, very good recyclability.
}},
author = {{Heim, Hans-Peter and Ries, Angela and Schöppner, Volker and Wibbeke,, Andrea and Turek, Stefan and Damanik, Hogenrich and Mahnken, Rolf and Dammann, Christian and Wünsch, Olaf and Al-Baldawi, Ammar and Rohde, Björn and Brückner-Foit, Angelika and Gausemeier, Jürgen and Gräßler, Iris and Petersen, Marcus}},
journal = {{Kunststoffe international}}},
pages = {{31--35}},
title = {{{Self-Reinforced Thermoplastic Composites - Composite Materials (Part 1)}}},
volume = {{104}},
year = {{2014}},
}
@article{28379,
abstract = {{Based on research results from the Collaborative Research Center Transregio 30, it is shown how composites made of self-reinforced, partially crystalline or highly stretched amorphous foils and fabrics for lightweight construction applications can be produced and which properties can be achieved. A locally differential, thermo-mechanical process control can be varied very efficiently, and thus graded properties can be set in the sense of functionalization.
}},
author = {{Heim, Hans-Peter and Ries, Angela and Schöppner, Volker and Wibbeke, Andrea and Turek, Stefan and Damanik, Hogenrich and Mahnken, Rolf and Dammann, Christian and Wünsch, Olaf and Al-Baldawi, Ammar and Rohde, Björn and Brükner-Foit, Angelika and Gausemeier, Jürgen and Gräßler, Iris and Petersen, Marcus}},
journal = {{Kunststoffe international}},
title = {{{Self-Reinforced Thermoplastic Composites - Composite Materials (Part 2)}}},
year = {{2014}},
}
@article{20945,
abstract = {{Calcium-Silicate-Hydrates (C-S-H) are the main binding phases in most concrete which is the primarily used composite construction material in the world. However, a big lack is cleaving between the actual knowledge about C-S-H, compared to what could be reached using state-of-the-art technologies of modern research. In this article, the formation of a C-S-H phase on a native oxide covered silicon wafer is investigated by means of in-situ attenuated total reflection infrared (ATR-IR) and ex-situ surface-enhanced Raman spectroscopy (SERS). The total thickness of the C-S-H phase is determined by X-ray photoelectron spectroscopy (XPS) to be 3 nm. The formation appears to be reversible depending on the environment pH value and can be performed at room temperature. Based on density functional theory (DFT) calculations, it is shown that the C-S-H phase in the presence of water will change its chemical composition in order to reach the thermodynamic ground state of the system. This change is achieved by a metal-proton exchange reaction. The stoichiometry of these metal-proton exchange reactions is nearly independent of the environment pH value. Electrokinetic measurements yield isoelectric points of 2.0 and 2.6 for the native oxide covered silicon wafer (SiO2) and the C-S-H phase. This is consistent with a predominance of Si-O sites at the C-S-H/water interface. (C) 2013 Elsevier B. V. All rights reserved.}},
author = {{Ebbert, Christoph and Grundmeier, Guido and Buitkamp, Nadine and Kroeger, Alexander and Messerschmidt, Florian and Thissen, Peter}},
issn = {{1873-5584}},
journal = {{APPLIED SURFACE SCIENCE}},
pages = {{207--214}},
title = {{{Toward a microscopic understanding of the calcium-silicate-hydrates/water interface}}},
doi = {{10.1016/j.apsusc.2013.11.045}},
volume = {{290}},
year = {{2014}},
}
@article{62785,
abstract = {{SUMMARYWe introduce a material model for the simulation of polycrystalline materials undergoing solid‐to‐solid phase‐transformations. As a basis, we present a scalar‐valued phase‐transformation model where a Helmholtz free energy function depending on volumetric and deviatoric strain measures is assigned to each phase. The analysis of the related overall Gibbs energy density allows for the calculation of energy barriers. With these quantities at hand, we use a statistical‐physics‐based approach to determine the resulting evolution of volume fractions. Though the model facilitates to take into account an arbitrary number of solid phases of the underlying material, we restrict this work to the simulation of phase‐transformations between an austenitic parent phase and a martensitic tension and compression phase. The scalar model is embedded into a computational micro‐sphere formulation in view of the simulation of three‐dimensional boundary value problems. The final modelling approach necessary for macroscopic simulations is accomplished by a finite element formulation, where the local material behaviour at each integration point is governed by the response of the micro‐sphere model.Copyright © 2014 John Wiley & Sons, Ltd.}},
author = {{Ostwald, Richard and Bartel, Thorsten and Menzel, Andreas}},
issn = {{0029-5981}},
journal = {{International Journal for Numerical Methods in Engineering}},
number = {{12}},
pages = {{851--877}},
publisher = {{Wiley}},
title = {{{A Gibbs‐energy‐barrier‐based computational micro‐sphere model for the simulation of martensitic phase‐transformations}}},
doi = {{10.1002/nme.4601}},
volume = {{97}},
year = {{2014}},
}
@article{62786,
author = {{Ostwald, Richard and Tiffe, Marcel and Bartel, Thorsten and Zabel, Andreas and Menzel, Andreas and Biermann, Dirk}},
issn = {{0924-0136}},
journal = {{Journal of Materials Processing Technology}},
number = {{8}},
pages = {{1516--1523}},
publisher = {{Elsevier BV}},
title = {{{Towards the multi-scale simulation of martensitic phase-transformations: An efficient post-processing approach applied to turning processes}}},
doi = {{10.1016/j.jmatprotec.2014.02.022}},
volume = {{214}},
year = {{2014}},
}
@misc{52441,
author = {{Schlüter, Alexander}},
title = {{{Energieeffizienter produzieren - Querschnitthemen und systemische Ansätze. Talk}}},
year = {{2014}},
}