@techreport{SieglEhrlichSiegletal., author = {Siegl, Marco and Ehrlich, Ingo and Siegl, Marco and Ehrlich, Ingo}, title = {Einfluss von Prozessparametern auf die Schmelzimpr{\"a}gnierung zur Herstellung von faserverst{\"a}rkten Thermoplasten}, series = {Forschung 2018 / Ostbayerische Technische Hochschule Regensburg}, journal = {Forschung 2018 / Ostbayerische Technische Hochschule Regensburg}, editor = {Baier, Wolfgang}, publisher = {VMK Verlag f{\"u}r Marketing \& Kommunikation GmbH \& Co. KG}, organization = {Ostbayerische Technische Hochschule Regensburg}, pages = {72 -- 73}, abstract = {Die Erforschung von faserverst{\"a}rkten Kunststoffen (FVK) mit thermoplastischer Matrix ist aufgrund der Schweißeignung als Verbindungstechnologie, der thermischen Umformbarkeit, der Recyclebarkeit sowie der verk{\"u}rzten Prozesszeiten im Vergleich zu den vorwiegend eingesetzten faserverst{\"a}rkten Duroplasten erstrebenswert. Die Wechselwirkung zwischen den physikalischen, mechanischen und geometrischen Parametern erh{\"o}ht den Komplexit{\"a}tsgrad des Herstellungsprozesses. Ziel ist daher die Entwicklung einer Impr{\"a}gniertechnik, die eine Fasertr{\"a}nkung mittels eines Thermoplastschmelzbades erm{\"o}glicht.}, language = {de} } @article{KastenmeierSieglEhrlichetal., author = {Kastenmeier, Andreas and Siegl, Marco and Ehrlich, Ingo and Gebbeken, Norbert}, title = {Review of elasto-static models for three-dimensional analysis of thick-walled anisotropic tubes}, series = {Journal of Composite Materials}, journal = {Journal of Composite Materials}, publisher = {Sage}, doi = {10.1177/00219983231215863}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-67521}, abstract = {Most shell or beam models of anisotropic tubes under bending have no validity for thick-walled structures. As a result, the need to develop three-dimensional formulations which allow a change in the stress, strain and displacement distributions across the radial component arises. Basic formulations on three-dimensional anisotropic elasticity were made either stressor displacement-based by Lekhnitskii or Stroh on plates. Lekhnitskii also was the first to expand these analytical formulations to tubes under various loading conditions. This paper presents a review of the stress and strain analysis of tube models using three-dimensional anisotropic elasticity. The focus lies on layered structures, like fiber-reinforced plastics, under various bending loads, although the basic formulations and models regarding axisymmetric loads are briefly discussed. One section is also dedicated to the determination of an equivalent bending stiffness of tubes.}, language = {en} } @article{PongratzTixWolfrumetal., author = {Pongratz, Christian and Tix, Janek and Wolfrum, Johannes and Gerke, Steffen and Ehrlich, Ingo and Br{\"u}nig, Michael}, title = {Test Setup for Investigating the Impact Behavior of Biaxially Prestressed Composite Laminates}, series = {Experimental Techniques}, journal = {Experimental Techniques}, publisher = {Springer Nature}, issn = {0732-8818}, doi = {10.1007/s40799-024-00701-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-70355}, pages = {14 S.}, abstract = {Instrumented impact testing and compression-after-impact testing are important to adequately qualify material behavior and safely design composite structures. However, the stresses to which fiber-reinforced plastic components are typically subjected in practice are not considered in the impact test methods recommended in guidelines or standards. In this paper, a test setup for investigating the impact behavior of composite specimens under plane uniaxial and biaxial preloading is presented. For this purpose, a special test setup consisting of a biaxial testing machine and a specially designed drop-weight tower was developed. The design decisions were derived from existing guidelines and standards with the aim of inducing barely visible impact damage in laminated carbon fiber-reinforced plastic specimens. Several measurement systems have been integrated into the setup to allow comprehensive observation of the impact event and specimen behavior. A feasibility test was performed with biaxially prestressed carbon fiber-reinforced plastic specimens in comparison with unstressed reference tests. The compressive-tensile prestressing resulted in lower maximum contact forces, higher maximum deflections, higher residual deflections and a different damage pattern, which was investigated by light microscopic analysis. Finally, the functionality of the experimental setup is discussed, and the results seem to indicate that the test setup and parameters were properly chosen to investigate the effect of prestresses on the impacts behavior of composite structures, in particular for barely visible subsequent damages.}, subject = {Faserverbundwerkstoff}, language = {en} } @article{PutzerEhrlichRasmussenetal., author = {Putzer, Michael and Ehrlich, Ingo and Rasmussen, John and Gebbeken, Norbert and Dendorfer, Sebastian}, title = {Sensitivity of lumbar spine loading to anatomical parameters}, series = {Journal of Biomechanics}, volume = {49}, journal = {Journal of Biomechanics}, number = {6}, publisher = {Elsevier Science}, doi = {10.1016/j.jbiomech.2015.11.003}, pages = {953 -- 958}, abstract = {Musculoskeletal simulations of lumbar spine loading rely on a geometrical representation of the anatomy. However, this data has an inherent inaccuracy. This study evaluates the influence of defined geometrical parameters on lumbar spine loading utilising five parametrised musculoskeletal lumbar spine models for four different postures. The influence of the dimensions of vertebral body, disc, posterior parts of the vertebrae as well as the curvature of the lumbar spine was studied. Additionally, simulations with combinations of selected parameters were conducted. Changes in L4/L5 resultant joint force were used as outcome variable. Variations of the vertebral body height, disc height, transverse process width and the curvature of the lumbar spine were the most influential. These parameters can be easily acquired from X-rays and should be used to morph a musculoskeletal lumbar spine model for subject-specific approaches with respect to bone geometry. Furthermore, the model was very sensitive to uncommon configurations and therefore, it is advised that stiffness properties of discs and ligaments should be individualised.}, subject = {Wirbels{\"a}ule}, language = {en} } @inproceedings{PutzerPenzkoferEhrlichetal., author = {Putzer, Michael and Penzkofer, Rainer and Ehrlich, Ingo and Rasmussen, John and Gebbeken, Norbert and Dendorfer, Sebastian}, title = {Musculoskeletal simulations to investigate the influence of vertebral geometrical parameters on lumbar spine loading}, series = {7th World Congress of Biomechanics, Boston, United States, 04/07/14 -11/07/14}, booktitle = {7th World Congress of Biomechanics, Boston, United States, 04/07/14 -11/07/14}, language = {de} } @inproceedings{SchmidJungbauerRomanoetal., author = {Schmid, Vinzent and Jungbauer, Bastian and Romano, Marco and Ehrlich, Ingo and Gebbeken, Norbert}, title = {The influence of different types of fabrics on the fibre volume content and porosity in basalt fibre reinforced plastics}, series = {2nd Applied Research Conference 2012 - ARC 25./26. June 2012}, booktitle = {2nd Applied Research Conference 2012 - ARC 25./26. June 2012}, editor = {Mottok, J{\"u}rgen and Ziemann, Olaf}, publisher = {Shaker}, pages = {162 -- 165}, abstract = {High quality semi-finished products with reproducible properties of basaltic fibres are hardly available on the market. In order to examine the properties of basalt fibre reinforced plastics high quality specimens are necessary. The fibre volume content and the porosity of the produced specimen are used as the typical criteria to evaluate the achieved quality of the produced material. The effect of the geometrical properties of the different semi-finished products on the fibre volume contents is relatively small whereas the porosity content is considerably affected.}, language = {en} } @inproceedings{LadewigSieglEhrlich, author = {Ladewig, Sven and Siegl, Marco and Ehrlich, Ingo}, title = {Discussion about Viscosity Theories for Fibre-Reinforced Thermoplastics}, series = {Applied Research Conference 2018 - ARC 2018, 10 July, Deggendorf}, booktitle = {Applied Research Conference 2018 - ARC 2018, 10 July, Deggendorf}, editor = {Mottok, J{\"u}rgen and Reichenberger, Marcus and Bogner, Werner}, publisher = {Pro Business Verlag}, address = {Berlin}, pages = {144 -- 149}, abstract = {The effect of process variables such as shear rate and temperature on the viscosity of polypropylene during the processing of thermoplastic based composites was investigated in this study. The melt impregnation is used in the process of continuous glass fibre reinforced thermoplastic composites. To develop a mathematical model for roving impregnation, it's essential to know about the viscous behaviour of the matrix system. Therefore, this paper will discuss rheological models to describe these phenomena, based on the gathered viscosity data from the partner laboratory at the University of West Bohemia in Pilsen.}, language = {en} } @inproceedings{SteinmannEhrlich, author = {Steinmann, Sven and Ehrlich, Ingo}, title = {Investigation of transverse impact stress in fiber reinforced plastics under high-velocity impact and determination of the experimental procedure}, series = {Applied Research Conference 2016 - ARC 2016, Augsburg, 24 June 2016}, booktitle = {Applied Research Conference 2016 - ARC 2016, Augsburg, 24 June 2016}, editor = {Mottok, J{\"u}rgen and Reichenberger, Marcus and Stolle, Reinhard}, publisher = {Pro Business Verlag}, address = {Berlin}, language = {en} } @inproceedings{SchmidJungbauerRomanoetal., author = {Schmid, Vinzent and Jungbauer, Bastian and Romano, Marco and Ehrlich, Ingo and Gebbeken, Norbert}, title = {Diminution of mass of different types of fibre reinforcements due to thermal load}, series = {Applied Research Conference 2012 - ARC 2012, 25./26. June 2012}, booktitle = {Applied Research Conference 2012 - ARC 2012, 25./26. June 2012}, editor = {Mottok, J{\"u}rgen and Ziemann, Olaf}, publisher = {Shaker}, pages = {231 -- 235}, language = {en} } @inproceedings{BohmannSchlampEhrlich, author = {Bohmann, T. and Schlamp, Matthias and Ehrlich, Ingo}, title = {Analysis of the Acoustic Emission Failure Frequencies of Glass Fiber Reinforced Composite Components}, series = {Applied Research Conference 2017 - ARC, 7 July 2017, M{\"u}nchen}, booktitle = {Applied Research Conference 2017 - ARC, 7 July 2017, M{\"u}nchen}, editor = {Klippel, Clemens and Mottok, J{\"u}rgen and Reichenberger, Marcus}, publisher = {Book-on-demand Verlag}, address = {Norderstedt}, pages = {369 -- 373}, language = {en} }