@inproceedings{DinnebierEhrlich, author = {Dinnebier, Heinrich and Ehrlich, Ingo}, title = {The Effects of Severe Temperature Changes and High Humidity on Porous CFRP}, series = {Proceedings of the 15th International Materials Symposium (IMSP´2014), Pamukkale University (Denizli, Turkey), 15./17. October 2014}, booktitle = {Proceedings of the 15th International Materials Symposium (IMSP´2014), Pamukkale University (Denizli, Turkey), 15./17. October 2014}, editor = {Meran, C.}, pages = {433 -- 440}, abstract = {Purpose: A route to manufacture porous carbon fiber reinforced plastic (CFRP) for study purposes is described. Design/methodology/approach: The porous CFRP is characterized using standard techniques such as matrix digestion as well as the more sophisticated method of high resolution Microfocus X-Ray Tomography (μCT). A comparison of the results of those methods is presented. The mass gains of specimens with a wide range of porosity have been measured both in constant humidity and in alternating environments. Findings: It could be shown that severe temperature changes can temporarily increase the moisture content of porous CFRP. However, after the return to a constant environment, the moisture content returns back to saturation levels. Furthermore, it could be shown by X-Ray Tomography that even under severe climatic conditions no permanent liquid water condensates inside the pores. Research limitations/implications: Using Microfocus Computed Tomography it could be shown that even after nearly a year under hot-wet conditions and more than 150 severe temperature cycles there is no liquid water detectable inside the pores. Originality/value: In this paper the effects of severe temperature changes and high humidity on porous CFRP.}, language = {en} } @inproceedings{EhrlichDinnebierJost, author = {Ehrlich, Ingo and Dinnebier, Heinrich and Jost, C.}, title = {Comparison of Impact Delaminations in CFRP Using Ultrasonic Testing, Microfocus Computed X-Ray Tomography and Micrographic Cross-Section}, series = {Proceeding of the 15th International Materials Symposium (IMSP´2014), Pamukkale University (Denizli, Turkey), 15./17. October 2014}, booktitle = {Proceeding of the 15th International Materials Symposium (IMSP´2014), Pamukkale University (Denizli, Turkey), 15./17. October 2014}, editor = {Meran, C.}, pages = {441 -- 450}, language = {en} } @inproceedings{Wenzl, author = {Wenzl, C.}, title = {Comparison of Analytical and Numerical Results for the Deformation of Circular Curved Structures under Pressure Load}, series = {Applied Research Conference 2018 - ARC 2018, 10 July 2018 Deggendorf}, booktitle = {Applied Research Conference 2018 - ARC 2018, 10 July 2018 Deggendorf}, editor = {Mottok, J{\"u}rgen and Reichenberger, Marcus and Bogner, Werner}, publisher = {Pro Business GmbH}, address = {Berlin}, isbn = {978-3-96409-018-8}, pages = {150 -- 155}, language = {en} } @inproceedings{FaberKastenmeierEhrlich, author = {Faber, M. and Kastenmeier, Andreas and Ehrlich, Ingo}, title = {Three-dimensional finite element analysis of a composite tube with multi-row bolted joints}, 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 = {de} } @inproceedings{Gebhardt, author = {Gebhardt, Jakob}, title = {Low Velocity Impact of GFRP Laminate - Experimental Observations and Numerical Modelling}, series = {Applied Research Conference 2018 - ARC 2018, 10 July 2018 Deggendorf}, booktitle = {Applied Research Conference 2018 - ARC 2018, 10 July 2018 Deggendorf}, editor = {Mottok, J{\"u}rgen and Reichenberger, Marcus and Bogner, Werner}, publisher = {Pro Business GmbH}, address = {Berlin}, isbn = {978-3-96409-018-8}, pages = {211 -- 215}, language = {en} } @inproceedings{IbanezGomezKastenmeierEhrlich, author = {Ibanez Gomez, D. and Kastenmeier, Andreas and Ehrlich, Ingo}, title = {Development and construction of a winding machine for the production of composite tubes}, series = {4th Applied Research Conference - ARC 2014, 5th July 2014, Ingolstadt}, booktitle = {4th Applied Research Conference - ARC 2014, 5th July 2014, Ingolstadt}, editor = {Ziemann, Olaf and Mottok, J{\"u}rgen and Pforr, Johannes}, publisher = {Shaker}, address = {Aachen}, pages = {315 -- 318}, language = {en} } @inproceedings{BrulandSchmidEhrlich, author = {Bruland, Matthias and Schmid, Vinzent and Ehrlich, Ingo}, title = {Analyzing and Testing of a Single Solution of Self-cutting Thread Inserts in Composites}, series = {Applied Research Conference 2014 - ARC 2014, 5th July 2014, Ingolstadt}, booktitle = {Applied Research Conference 2014 - ARC 2014, 5th July 2014, Ingolstadt}, editor = {Ziemann, Olaf and Mottok, J{\"u}rgen and Pforr, Johannes}, publisher = {Shaker}, pages = {286 -- 288}, language = {en} } @article{SchimmerLadewigMotschetal., author = {Schimmer, Florian and Ladewig, Sven and Motsch, Nicole and Hausmann, Joachim M. and Ehrlich, Ingo}, title = {Comparison of Low-Velocity Impact Damage Behavior of Unidirectional Carbon Fiber-Reinforced Thermoset and Thermoplastic Composites}, series = {Key Engineering Materials}, volume = {809}, journal = {Key Engineering Materials}, publisher = {Trans Tech Publications}, issn = {1662-9795}, doi = {10.4028/www.scientific.net/KEM.809.9}, pages = {9 -- 14}, abstract = {This paper investigates the damage behavior of thermoset and thermoplastic fiber-reinforced composites. The specimens were subjected to low-velocity impacts (LVI) to produce barely visible impact damages (BVID). To compare the dependency of the matrix system and the laminate lay-up on the impact damage, four test series were set up. Therefore, laminates with an epoxy (EP) and a polyether ether ketone (PEEK) matrix in a quasi-isotropic (QI) [+45/0/-45/90]2s and an orthotropic (OT) fiber lay-up [0/90]4s were manufactured. To eliminate the influence of variant fiber systems, the thermoplastic tape and the thermoset prepreg contain similar carbon fibers (CF). After impact testing with three different impact energies, inner damages were investigated by using ultrasonic analyses. To get a deeper understanding of the interior damage mechanisms, cross sections of the damaged areas were examined via reflected light microscopy. By using these destructive and non-destructive test methods, significant differences in the damage behavior of composites with thermoplastic and thermoset matrix systems were identified for both laminate lay-ups.}, language = {en} } @inproceedings{SieglRiegerKovariketal., author = {Siegl, Marco and Rieger, David and Kov{\´a}r{\´i}k, Tom{\´a}š and Ehrlich, Ingo}, title = {Long-Term Behavior of Thermoplastics under UV Light tested by a self-build Device}, series = {3. OTH-Clusterkonferenz, 13. April 2018, Weiden, Tagungsband; Festschrift, 5 Jahre OTH-Verbund}, booktitle = {3. OTH-Clusterkonferenz, 13. April 2018, Weiden, Tagungsband; Festschrift, 5 Jahre OTH-Verbund}, organization = {Ostbayerische Technische Hochschule}, pages = {118 -- 122}, abstract = {This article presents first results of artificial aging experi-ments by ultraviolet (UV) irradiation on thermoplasticmaterials conducted as an intent of the research project Thermoplastic Composite Structures (TheCoS) in colla-boration of the Ostbayerische Technische Hochschule(OTH) Regensburg and the University of West Bohemia(UWB) in Pilsen as part of a cross-border cooperation. In technical applications, thermoplastic materials are oftenaffected by aging and a related deterioration of the mechanical properties. Therefore, it is necessary to identifythe aging behavior of thermoplastic materials. For this,experiments were performed for three thermoplasticmaterials, namely polypropylene (PP), ultra high mole -cular weight polyethylene (UHMWPE) and high impactstrength polystyrene (HIPS). For these experiments, a UV chamber was constructed according to the internationalstandard EN ISO 4892-3 for simulation of exposurebehind window glass. The results are evaluated by testing the flexural strength and the dynamic mechanicalresponse after a selected period of time under UV lightand then compared to untreated test specimens.}, language = {en} } @inproceedings{ValentinoRomanoEhrlichetal., author = {Valentino, Piergiorgio and Romano, Marco and Ehrlich, Ingo and Furgiuele, Franco and Gebbeken, Norbert}, title = {Mechanical characterization of basalt fibre reinforced plastic with different fabric reinforcements - Tensile tests and FE-calculations with representative volume elements (RVEs)}, series = {Acta Fracturae - XXll Convegno Nazionale IGF (Italiano Gruppo Frattura)}, booktitle = {Acta Fracturae - XXll Convegno Nazionale IGF (Italiano Gruppo Frattura)}, editor = {Iacovello, F. and Risitano, G. and Susmel, L.}, abstract = {This paper describes the results of tensile tests and finite element (FE) calculations with representative volume elements (RVEs) of basalt fibre reinforced plastic with two different types of fabric reinforcements. As fabric reinforcements show repeating ondulations of warp and fill yarn, simple mixtures laws reach their limits. That is the reason why the mesoscopic dimension, lying between the microscopic and the macroscopic dimension, has to be taken into account when a mechanical characterization of fabric reinforced composites is carried out. The aim of this work is to determine the stiffness of a fabric reinforced composite in warp and fill direction with numerical investigations. The simulations are based on FE-calculation with two different RVEs. The tensile tests and the FE-calculations have been carried out for two different types of basalt fabrics, namely twill 2/2 and twill 1/3. The comparison between the experimental data and the results of the FE-calculations are provided in order to support the validity of the proposed model.}, language = {en} } @inproceedings{Seppenhauser, author = {Seppenhauser, P.}, title = {Examinations of the Printer Head Prototype for UV Resins with Continous Fiber-Reinforcement}, series = {Applied Research Conference 2019 - ARC 2019, 8 July 2019, Regensburg}, booktitle = {Applied Research Conference 2019 - ARC 2019, 8 July 2019, Regensburg}, editor = {Mottok, J{\"u}rgen and Reichenberger, Marcus}, publisher = {Pro Business GmbH}, address = {Berlin}, isbn = {978-3-96409-182-6}, pages = {241 -- 248}, subject = {3D-Druck}, language = {en} } @article{MicklitzRomanoEhrlichetal., author = {Micklitz, Matthias and Romano, Marco and Ehrlich, Ingo and Gebbeken, Norbert}, title = {The influence of ondulations in fabric reinforced layers on the damping properties of fibre-reinforced plastics}, series = {Applied Research Conference 2014 - ARC 2014, 5th July 2014, Ingolstadt}, journal = {Applied Research Conference 2014 - ARC 2014, 5th July 2014, Ingolstadt}, editor = {Ziemann, Olaf and Mottok, J{\"u}rgen and Pforr, Johannes}, publisher = {Shaker}, address = {Aachen}, pages = {306 -- 310}, language = {de} } @inproceedings{NiebauerSchmidEhrlich, author = {Niebauer, M. and Schmid, Vinzent and Ehrlich, Ingo}, title = {Failure Criteria of Adhesively Bonded Joints}, series = {Applied Research Conference 2015 - ARC 2015, N{\"u}rnberg, 3rd July 2015 - 16. Juli 2015}, booktitle = {Applied Research Conference 2015 - ARC 2015, N{\"u}rnberg, 3rd July 2015 - 16. Juli 2015}, editor = {Mottok, J{\"u}rgen and Reichenberger, Marcus and Scharfenberg, J. and Ziemann, Olaf}, publisher = {Pro Business Verlag}, address = {Berlin}, isbn = {978-3863869458}, pages = {347 -- 351}, language = {en} } @article{DinnebierEhrlich, author = {Dinnebier, Heinrich and Ehrlich, Ingo}, title = {The effects of severe temperature changes and high humidity on porous CFRP}, series = {Journal of Achievements in Materials and Manufacturing Engineering (JAMME)}, volume = {67}, journal = {Journal of Achievements in Materials and Manufacturing Engineering (JAMME)}, number = {1}, pages = {14 -- 20}, abstract = {Purpose: A route to manufacture porous carbon fiber reinforced plastic (CFRP) for study purposes is described. Design/methodology/approach: The porous CFRP is characterized using standard techniques such as matrix digestion as well as the more sophisticated method of high resolution Microfocus X-Ray Tomography (μCT). A comparison of the results of those methods is presented. The mass gains of specimens with a wide range of porosity have been measured both in constant humidity and in alternating environments. Findings: It could be shown that severe temperature changes can temporarily increase the moisture content of porous CFRP. However, after the return to a constant environment, the moisture content returns back to saturation levels. Furthermore, it could be shown by X-Ray Tomography that even under severe climatic conditions no permanent liquid water condensates inside the pores. Research limitations/implications: Using Microfocus Computed Tomography it could be shown that even after nearly a year under hot-wet conditions and more than 150 severe temperature cycles there is no liquid water detectable inside the pores. Originality/value: In this paper the effects of severe temperature changes and high humidity on porous CFRP.}, language = {en} } @techreport{EisenriedRomanoJungbaueretal., author = {Eisenried, Michael and Romano, Marco and Jungbauer, Bastian and Ehrlich, Ingo and Gebbeken, Norbert}, title = {Herstellung von unidirektional verst{\"a}rkten Prepregs im Labormaßstab - Einfluss von Fertigungsparametern auf die Materialqualit{\"a}t}, series = {Forschungsbericht 2013 / Ostbayerische Technische Hochschule Regensburg}, journal = {Forschungsbericht 2013 / Ostbayerische Technische Hochschule Regensburg}, address = {Regensburg}, pages = {51 -- 52}, language = {de} } @phdthesis{Ehrlich, author = {Ehrlich, Ingo}, title = {Impactverhalten schwach gekr{\"u}mmter Strukturen aus faserverst{\"a}rkten Kunststoffen}, address = {M{\"u}nchen}, language = {de} } @article{BodeEhrlich, author = {Bode, J. and Ehrlich, Ingo}, title = {Entwicklung eines finiten Elements f{\"u}r Sandwichanwendungen}, series = {Zeitschrift f{\"u}r Angewandte Mathematik und Mechanik (ZAMM), Journal of Applied Mathematics and Mechanics}, volume = {77}, journal = {Zeitschrift f{\"u}r Angewandte Mathematik und Mechanik (ZAMM), Journal of Applied Mathematics and Mechanics}, number = {1}, pages = {41 -- 42}, language = {de} } @article{RomanoHoinkesEhrlichetal., author = {Romano, Marco and Hoinkes, Carl J. J. and Ehrlich, Ingo and H{\"o}cherl, Johannes and Gebbeken, Norbert}, title = {Experimental investigation of energy dissipation properties of fibre reinforced plastics with hybrid layups under high-velocity impact loads}, series = {Journal of Achievements in Materials and Manufacturing Engineering (JAMME)}, volume = {64}, journal = {Journal of Achievements in Materials and Manufacturing Engineering (JAMME)}, number = {1}, pages = {14 -- 20}, abstract = {Purpose: The present work deals with the experimental investigation concerning the energy dissipation capacity of different kinds of reinforcement fibres in monolithic and hybrid layups under high velocity impact loads. The investigated kinds of fibres are carbon, glass and basalt. Design/methodology/approach: The test panels have been impregnated with thermoset resin. Curing was done by autoclave processing. In order to obtain comparable fibre volume contents of approx. 60 \% in the different layups (monolithic and hybrid without and with separating layer), curing cycles adapted to the type of layup have been identified. The resulting fibre volume content of the test panels has been determined both by weighing and experimentally by chemical extraction and calcination. The impact load was applied by an instrumented experimental setup. Thereby both commercially available bullets and bearing balls accelerated with weighted propellant in a sabot have been used as impactors. The measured values are the velocities of the bearing balls as the impactor before and after penetration of the test panels. Findings: In both cases the results show the energy dissipation capacity of each single kind of fibre in case of the monolithic layups as well as the enhanced properties of the hybrid stacked layups without and with the separating layer as a core material. Typical failure modes on the impact surface and on the outlet areas are identified. Research limitations/implications: The influence of the respective kind of impactors, namely bullets and bearing balls, on the evaluated results is identified. Thereby the bearing balls exhibited a higher degree of reproducibility due to several reasons. Originality/value: Fibre reinforced plastics with hybrid stacking sequences can be used as load-bearing structures and at the same time as safety structures for passengers in automotive or aerospace applications. Moreover, with the hybrid stacked composites lightweight concepts can efficiently be realized regarding energy saving issues.}, language = {en} } @article{SieglEhrlich, author = {Siegl, Marco and Ehrlich, Ingo}, title = {Transformation of the Mechanical Properties of Fiber-Reinforced Plastic Tubes from the Cartesian Coordinate System into the Cylindrical Coordinate System for the Application of Bending Models}, series = {Athens Journal of Technology \& Engineering}, volume = {4}, journal = {Athens Journal of Technology \& Engineering}, number = {1}, pages = {47 -- 62}, abstract = {Fiber-reinforced plastic (FRP) tubes are used in many different industries, such as electrical engineering and pipeline construction. The tubes are frequently subjected to bending loads, depending on the application. In order that the dimensioning of the tubes can be ensured, analytical bending models are used to calculate the resulting stresses, strains and displacements in the individual layers of the laminate. This enables the making of a statement about the failure of the fiber-reinforced tube by choosing an appropriate failure criterion. For the use of these bending models, it is necessary to understand the respective underlying theory. The theory provides the basis for the mathematical description of the mechanical properties for a single-layered tube and using the relationships between the stresses and strains that occur in the Cylindrical coordinate system for this calculation step. For this reason, a redefinition of the compliance matrix from the transformation about the winding angle to the Cylindrical coordinate system and a modification of the stress and strain vectors is necessary, because the defined Cartesian coordinate system of the model cannot be used for wounded FRP tubes. The transformation causes an exchange of entries in the compliance matrix, which remain in the correct relationship between the particular stress and strains. This step is not specified and may lead to incorrect results due to the incorrect entry of compliances. The present publication refers to sketch on this issue and represent a simplification of the changeover to the level required by the bending models notation of vectors in the form of a permutation. In addition, a new name for the pre-acquisition of the redefined compliances is given to prevent confusion when entering the material law of a bending model. Finally, the permuted and redefined compliances are proved in an example to determine their accuracy.}, language = {en} } @article{RomanoEhrlichGebbeken, author = {Romano, Marco and Ehrlich, Ingo and Gebbeken, Norbert}, title = {Parametric characterization of a mesomechanic kinematic in plain and twill weave 2/2 reinforced composites by FE-calculations}, series = {Archives of Materials Science and Engineering (ArchivesMSE)}, volume = {97}, journal = {Archives of Materials Science and Engineering (ArchivesMSE)}, number = {1-2}, publisher = {Index Copernicus}, issn = {1897-2764}, doi = {10.5604/01.3001.0013.2869}, pages = {20 -- 38}, abstract = {Purpose: A parametric characterization of a mesomechanic kinematic caused by ondulation in fabric reinforced composites is investigated by numerical investigations. Design/methodology/approach: Due to the definition of plain representative sequences of balanced plain-weave and twill-weave 2/2 fabric reinforced single layers based on sines the variable geometric parameters are the amplitude and the length of the ondulation. Findings: The mesomechanic kinematic can be observed in the FE analyses for both kinds of fabric constructions. Research limitations/implications: The FE analyses consider elasticity and contraction due to Poisson effects, respectively, of the model under selected longitudinal strains. Practical implications: The results are evaluated at relevant positions on the centre-line of the ondulated warp-yarn of the plain representative model. A direct and linear coupling in case of the transversal kinematic behaviour, and thereby a corresponding definite reduction of the evaluated longitudinal strains in terms of the difference of the applied and determined longitudinal strains is identified. Originality/value: Both characteristic purely kinematic reactions due to geometric constraints directly depend on the introduced degree of ondulation. This non-dimensional parameter relates amplitude and length of one complete ondulation, and thus represents the intensity of the ondulation of the respective fabric construction.}, language = {en} } @article{RomanoEhrlichGebbeken, author = {Romano, Marco and Ehrlich, Ingo and Gebbeken, Norbert}, title = {Structural mechanic material damping in fabric reinforced composites}, series = {Archives of Materials Science and Engineering (ArchivesMSE)}, volume = {88}, journal = {Archives of Materials Science and Engineering (ArchivesMSE)}, number = {1}, doi = {10.5604/01.3001.0010.7747}, pages = {12 -- 41}, abstract = {Purpose: A review regarding the acting mechanisms of structural dynamic material damping in fabric reinforced composites is presented. Design/methodology/approach: Mechanical acting principles identified by different investigations are considered. Aspects of the determination and calculation of structural mechanical material properties of fabric reinforced composites are described. Approaches intending the description and classification of ondulations in fabrics reinforced single layers are demonstrated. Findings: The mesomechanic geometry of fabrics is not considered sufficiently by relatively simple homogenization approaches. Yet, it significantly affects its structural dynamic material properties, especially the dynamic ones. Research limitations/implications: In each case the different damping mechanisms act coupled and occur at the same time. Therefore a separation procedure is required in any case. Practical implications: Against the background of the comparison and remarks of the presented papers a reasonable further procedure is recommended. Thereby, FE-calculations with a parametrical variation of the mesomechanic geometry in order to identify kinematic correlations due to geometric constraints are suggested. Originality/value: The idea of the representation of the geometric conditions in terms of a degree of ondulation is described. Such a non-dimensional specific value representing the intensity of the ondulation would enable the comparability of the results of different kinds of investigations.}, language = {en} } @article{ValentinoSgambitterraFurgiueleetal., author = {Valentino, Piergiorgio and Sgambitterra, Emanuele and Furgiuele, Franco and Romano, Marco and Ehrlich, Ingo and Gebbeken, Norbert}, title = {Mechanical characterization of basalt woven fabric composites}, series = {Frattura ed Integrit{\`a} Strutturale (Fracture and Structural Integrity)}, volume = {8}, journal = {Frattura ed Integrit{\`a} Strutturale (Fracture and Structural Integrity)}, number = {28}, doi = {10.3221/IGF-ESIS.28.01}, pages = {1 -- 11}, abstract = {Basalt fabric composite, with different twill wave reinforcements, i.e. twill 2/2 and twill 1/3, have been studied in this work by means of experimental tests and numerical finite element (FE) simulations. As fabric reinforcements show repeating undulations of warp and fill yarn, simple mixtures law cannot be applied. As a consequence, the mesoscopic scale, lying between the microscopic and the macroscopic one, has to be taken into account to mechanically characterize a fabric reinforced composite. The aim of this work is to evaluate the stiffness of a fabric reinforced composite in warp and fill direction. In particular a numerical FE model, assuming elliptical sections and sinusoidal shape of the yarns, has been implemented and experimental tests have been carried out in order to validate the proposed model. Finally, the strength and the failure modes le orientation, have been experimentally investigated.}, language = {en} } @techreport{SchlampEhrlich, author = {Schlamp, Matthias and Ehrlich, Ingo}, title = {Analyse des Impact-Verhaltens gekr{\"u}mmter Strukturbauteile von Luftfahrzeugen zur Entwicklung eines Struktur{\"u}berwachungssystems f{\"u}r faserverst{\"a}rkte Kunststoffe - BIRD}, series = {Forschung 2019 / Ostbayerische Technische Hochschule Regensburg}, journal = {Forschung 2019 / Ostbayerische Technische Hochschule Regensburg}, editor = {Baier, Wolfgang}, publisher = {VMK Verlag f{\"u}r Marketing \& Kommunikation GmbH \& Co. KG}, organization = {Ostbayerische Technische Hochschule Regensburg}, isbn = {978-3-9818209-6-6}, pages = {40 -- 41}, abstract = {Die in Flugvorausrichtung weisenden Bauteile von Luftfahrzeugen sind oftmals durch Einschl{\"a}ge aufgrund von Vogelschlag, Hagel oder aufgewirbelten Kleinteilen gef{\"a}hrdet. Diese Einschl{\"a}ge, sogenannte Impacts, weisen bei faserverst{\"a}rkten Kunststoffen ein stark kr{\"u}mmungs- und materialabh{\"a}ngiges Verhalten und Schadensausmaß auf. Impact-Sch{\"a}digungen f{\"u}hren oftmals zu hohen Reparaturkosten, welche durch eine genauere Kenntnis des Schadens verringert werden k{\"o}nnen. Zur Klassifizierung dieser Sch{\"a}digungen steht dabei vor allem das auftretende Frequenz signal des Impacts im Fokus der Untersuchungen.}, language = {de} } @article{RomanoHoinkesEhrlichetal., author = {Romano, Marco and Hoinkes, Carl J. J. and Ehrlich, Ingo and H{\"o}cherl, Johannes and Gebbeken, Norbert}, title = {Experimental investigation of fibre reinforced plastics with hybrid layups under high-velocity impact loads}, series = {Frattura ed Integrit{\`a} Strutturale (Fracture and Structural Integrity)}, volume = {8}, journal = {Frattura ed Integrit{\`a} Strutturale (Fracture and Structural Integrity)}, number = {29}, doi = {10.3221/IGF-ESIS.29.34}, pages = {384 -- 398}, abstract = {This paper deals with experimental investigations concerning energy dissipation capacity of different kinds of reinforcement fibres in monolithic and hybrid layups under high-velocity impact loads. The investigated kinds of fibres are carbon, glass and basalt fibres. Therefore test panels, using the same thermoset resin, were built up and cured by autoclave processing. The fibre volume content of the test panels has been determined. Furthermore the influence of a separating layer at selected positions in the hybrid stacked panels was investigated. The results show the influence and the energy dissipation capacity of each single kind of fibre and the enhanced properties for the hybrid layups by hybrid stacking sequences and the use of a separating core material.}, language = {en} } @techreport{PutzerRasmussenEhrlichetal., author = {Putzer, Michael and Rasmussen, John and Ehrlich, Ingo and Gebbeken, Norbert and Dendorfer, Sebastian}, title = {Muskuloskelettale Simulation zur Untersuchung des Einflusses geometrischer Parameter der Wirbelk{\"o}rper auf die Belastung der Lendenwirbels{\"a}ule}, series = {Forschungsbericht 2013 / Ostbayerische Technische Hochschule Regensburg}, journal = {Forschungsbericht 2013 / Ostbayerische Technische Hochschule Regensburg}, editor = {Baier, Wolfgang}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg}, pages = {60 -- 61}, language = {de} } @article{RomanoMicklitzOlbrichetal., author = {Romano, Marco and Micklitz, Matthias and Olbrich, Florian and Bierl, Rudolf and Ehrlich, Ingo and Gebbeken, Norbert}, title = {Experimental investigation of damping properties of unidirectionally and fabric reinforced plastics by the free decay method}, series = {Journal of Achievements in Materials and Manufacturing Engineering}, volume = {63}, journal = {Journal of Achievements in Materials and Manufacturing Engineering}, number = {2}, pages = {65 -- 80}, abstract = {Purpose: of this paper is experimental investigation of damping properties of unidirectionally and fabric reinforced plastics by the free decay method. Design/methodology/approach: For the evaluation of the presumed effect experimental structural dynamic investigations comparing unidirectionally and fabric reinforced plastics are carried out. In detail the free decay behaviour of flat beamlike specimens under fixed-free boundary conditions and relatively constant and reproducible displacement excitation is investigated. Findings: The vibrating structure has been measured by a laser scanning vibrometer PSV 400 from POLYTEC. In both cases evaluation of the results yields enhanced damping properties of the specimens with fabric reinforcement compared to the unidirectionally reinforced specimens. The results justify the presumed acting of a mesomechanic kinematic. Research limitations/implications: The results show that in either case the material damping in terms of the logarithmic decrement of the fabric reinforced material is higher than the material damping in of the unidirectionally reinforced material. Additionally, when the fabric reinforced specimens are addressed, in each case the plain weave reinforced specimens exhibited higher values of the material damping as the twill weave 2/2 reinforced ones. Originality/value: Ondulations in fabrics as a textile semi-finished product are caused by the alternating crossing of warp and fill yarns. In the mesoscopic scale the acting of a mesomechanic kinematic is presumed to enhance the damping properties under cyclic elastic deformation. For the evaluation of the presumed effect experimental structural dynamic investigations comparing unidirectionally and fabric reinforced plastics are carried out.}, language = {en} } @techreport{SieglEhrlich, author = {Siegl, Marco and Ehrlich, Ingo}, title = {Internationale Forschung zum Biege- und Deformationsverhalten von faserverst{\"a}rkten Kunststoffrohren}, series = {Forschung 2019 / OTH Regensburg}, journal = {Forschung 2019 / OTH Regensburg}, editor = {Baier, Wolfgang}, publisher = {VMK Verlag f{\"u}r Marketing \& Kommunikation}, organization = {Ostbayerische Technische Hochschule Regensburg}, isbn = {978-3-9818209-6-6}, pages = {42 -- 43}, language = {de} } @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} } @phdthesis{Schlamp, author = {Schlamp, Matthias}, title = {Der Einfluss elliptischer Kr{\"u}mmung auf das Verformungs- und Sch{\"a}digungsverhalten glasfaserverst{\"a}rkter Kunststoffstrukturen}, doi = {10.6094/UNIFR/228064}, pages = {169}, abstract = {In Industriebereichen, in welchen Masse aufgrund von Tr{\"a}gheit oder Gravitations{\"u}berwindung einen beeinflussenden Faktor ausmacht, wie beispielsweise der Luft- und Raumfahrt oder der Windkraft, spielen faserverst{\"a}rkte Kunststoffstrukturen aufgrund ihres Leichtbaupotentials hinsichtlich der dichtespezifischen Steifigkeit und Festigkeit eine große Rolle. Außen liegende Bauteile in Form d{\"u}nnwandiger Fl{\"a}chentragwerke in diesen Anwendungen weisen zumeist nicht eine kreisrunde, sondern unstetige Bauteilkr{\"u}mmung auf und sind aufgrund ihres Einsatzortes durch Schlagbelastungen (Impacts) in verschiedenen Geschwindigkeitsbereichen gef{\"a}hrdet. Besonders im Niedergeschwindigkeitsbereich sind diese Impacts bei diesen meist gekr{\"u}mmten Strukturen als kritisch zu beurteilen, da sie von außen oftmals nicht sichtbar sind, sich aber stark auf die verbleibende Restfestigkeit, insbesondere die Druck- und Schwingfestigkeit, aufgrund inter- und intralaminarer Sch{\"a}digungen auswirken. Sie stellen demnach eine kritisch zu betrachtende Belastungsart dar. In der vorliegenden Arbeit werden oben benannte unstetig gekr{\"u}mmte Fl{\"a}chentragwerke auf eine unstetig elliptisch gekr{\"u}mmte Pr{\"u}fk{\"o}rpergeometrie in Anlehnung an den Querschnitt einer Fl{\"u}gelvorderkante abstrahiert. Mittels experimenteller, numerischer und analytischer Untersuchungen wird ein grundlegendes Verst{\"a}ndnis des Kr{\"u}mmungseinflusses auf das Sch{\"a}digungs- und Verformungsverhalten ebendieser Strukturen bei Impact-Belastung und quasi-statischer Druckbelastung erarbeitet. Pr{\"u}fk{\"o}rper mit vier verschiedenen Kr{\"u}mmungsstufen werden dahingehend unter Verwendung einer Fallbolzenanlage im Niedergeschwindigkeitsbereich sch{\"a}digend gepr{\"u}ft und die resultierende projizierende Schadensfl{\"a}che in Abh{\"a}ngigkeit des Kr{\"u}mmungsgrades ausgewertet. Zur Untersuchung des reinen Kr{\"u}mmungseinflusses werden Pr{\"u}fk{\"o}rper in quasistatischen Druckversuchen im elastischen Bereich auf deren Verformungsverhalten hin analysiert. Durch Einf{\"u}hrung des geometriebedingten Verformungswiderstandes als vergleichende Kenngr{\"o}ße kann auf Basis lokal variierender Struktursteifigkeiten ein Zusammenhang aus dem Impact-Verhalten und dem elastischen Verformungsverhalten gleicher Kr{\"u}mmungsstufen geschlossen werden. Durch begleitende numerische Untersuchungen wird das Verformungsverhalten sowie die sich dabei einstellenden einzelschichtspezifischen Spannungszust{\"a}nde untersucht. Weiterhin werden bestehende analytische Berechnungsmethoden f{\"u}r stetige Kreisb{\"o}gen im Berechnungsumfang erweitert und auf die vorliegende Problemstellung{\"u}bertragen. Eine Gegen{\"u}berstellung und Diskussion aller erfassten Versuchs- und Berechnungsergebnisse zeigt abschließend gemeinsame Abh{\"a}ngigkeiten auf.}, language = {de} } @phdthesis{Kastenmeier, author = {Kastenmeier, Andreas}, title = {Biegeverhalten faserverst{\"a}rkter Kunststoffrohre unter Ber{\"u}cksichtigung einer mehrreihigen Bolzenverbindung}, pages = {260}, abstract = {In der vorliegenden Arbeit wird die Charakterisierung des mechanischen Verhaltens von auskragenden Rohren aus kohlenstofffaserverst{\"a}rktem Kunststoff (CFK) mit Querkraftbelastung an einem Ende und einer mehrreihigen Bolzenverbindung am anderen Ende behandelt. Bolzenverbindungen mit F{\"u}gepartner aus CFK werden im Stand der Technik nur an ebenen, zug- oder druckbelasteten, Verbindungen untersucht, weshalb der Einfluss der Biegebelastung, der gekr{\"u}mmten Auflagefl{\"a}chen und des geschlossenen Rohrprofils untersucht und qualifiziert wird. Zudem zeigt sich ein Effekt der Abst{\"u}tzung bzw. resultierenden Verformungsbehinderung. Die Grundlage der Untersuchungen bilden 2-Punkt-Biegeversuche mit Verzerrungs- und Verschiebungsmessungen, die {\"u}ber FE-Modelle numerisch abgebildet und in einer Verzerrungs- und Spannungsanalyse detaillierter ausgewertet werden. Zur Darstellung des Einflusses der Biegebelastung werden zudem reine Zug- und Drucklasten aufgebracht, ausgewertet und abgeglichen. In drei Variationen des Biegeversuchs werden zudem, sowohl experimentell als auch numerisch, Effekte zu einer m{\"o}glichen Steigerung der Verbindungsfestigkeit untersucht. Dazu z{\"a}hlt die Verwendung von zus{\"a}tzlichen Schichten aus Titanlegierung im Kraft{\"u}berleitungsbereich, ein Versetzen der Bolzen im Umfang und eine {\"A}nderung der Abst{\"u}tzung in Lastrichtung. F{\"u}r das Biegeverhalten der CFK-Rohre im frei auskragenden Bereich werden kontinuumsmechanische Modelle der anisotropen Elastizit{\"a}t f{\"u}r Rohre unter reiner Biegebelastung beschrieben, adaptiert und bez{\"u}glich der Ergebnisse bewertet. Um die Vergleichbarkeit der Berechnungsmodelle und Versuche zu gew{\"a}hrleisten, wird einerseits der Einfluss der speziellen Schichtstruktur in gewickelten CFK-Rohren diskutiert und andererseits werden die transversal-isotropen Materialeigenschaften der Einzelschicht an Probek{\"o}rpern aus den Rohren bestimmt.}, subject = {Kunststoffrohr}, language = {de} } @inproceedings{JudenmannHoltmannspoetterEhrlich, author = {Judenmann, Anna and Holtmannsp{\"o}tter, Jens and Ehrlich, Ingo}, title = {Additive Manufacturing of Continuous Fiber-Reinforced Composites}, series = {Proceedings of the Munich Symposium on Lightweight Design 2022}, booktitle = {Proceedings of the Munich Symposium on Lightweight Design 2022}, language = {de} } @article{SieglJungbauerGebhardtetal., author = {Siegl, Marco and Jungbauer, Bastian and Gebhardt, Jakob and Judenmann, Anna and Ehrlich, Ingo}, title = {Winding process of fibre-reinforced thermoplastic tubes with integrated tape production through in-situ roving impregnation and infrared consolidation}, series = {The International Journal of Advanced Manufacturing Technology}, volume = {135}, journal = {The International Journal of Advanced Manufacturing Technology}, number = {5-6}, editor = {Baeten, Somayeh}, publisher = {Springer Nature}, doi = {10.1007/s00170-024-14628-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-77827}, pages = {2847 -- 2870}, abstract = {This paper introduces a novel method for producing fibre-reinforced thermoplastic tubes by integrating tape production and consolidation into a single operation. This innovation diverges from conventional methods by combining processes to reduce costs by using raw materials instead of organotapes, allowing customised material combinations and utilising residual heat from tape production. The new process uses carbon roving and molten low-viscosity PA6 granulates, processed through a new direct impregnation setup in siphon design. Key advancements include a high-speed impregnation module capable of up to 1 m/s with high-performance extruders, cost-effective infrared emitters for winding, and a powered consolidation unit with adjustable winding angles between ±65° and ±90°. Experiments demonstrate operational speeds of approximately 471 mm/min, with an optimal cross-winding speed of 354 mm/min due to the technical limitations of the laboratory extruder and IR emitter used. Based on the technical limitations of the current system, future improvements and methodological changes will be discussed.}, language = {en} } @article{AndraeKastenmeierGebhardtetal., author = {Andrae, Matthias and Kastenmeier, Andreas and Gebhardt, Jakob and Ehrlich, Ingo and Gebbeken, Norbert}, title = {Shock-tube tests on conventional windows: Exploring retrofit concepts for enhanced blast protection}, series = {International Journal of Protective Structures}, journal = {International Journal of Protective Structures}, publisher = {SAGE}, issn = {2041-4196}, doi = {10.1177/20414196241284297}, abstract = {Ensuring blast protection for existing buildings, especially addressing the vulnerability of conventional windows, is a significant challenge. Such unprotected windows can shatter even with moderate blast loads, posing a substantial risk of injury to occupants. This article discusses experimental research on enhancing the blast protection of single casement windows with insulating glass units and frames made of unplasticized polyvinyl chloride (uPVC). A retrofit concept using anti-shatter films, metallic sash reinforcements, adhesive bonding of the glazing to the sash frame, and a burglary resistance fitting-system was developed and tested in an explosion-driven shock-tube. Moreover, novel patches made of glass fiber-reinforced polymer applied to the corners of the window frames have been tested and proven effective in providing additional strength to the window. The study concludes that the tested combination of retrofit measures can significantly reduce hazards from window fragments without compromising functionality or aesthetics.}, language = {en} } @inproceedings{RomanoHoinkesEhrlichetal., author = {Romano, Marco and Hoinkes, Carl J. J. and Ehrlich, Ingo and H{\"o}cherl, Johannes and Gebbeken, Norbert}, title = {Influence of the impactor on the experimentally determined energy dissipation properties of fiber-reinforced plastics with hybrid layups under high velocity impact loads}, series = {Proceeding of the 15th International Materials Symposium (IMSP´2014), Pamukkale University (Denizli, Turkey), 15./17. October 2014}, booktitle = {Proceeding of the 15th International Materials Symposium (IMSP´2014), Pamukkale University (Denizli, Turkey), 15./17. October 2014}, editor = {Meran, C.}, pages = {650 -- 664}, language = {en} } @inproceedings{HoinkesRomanoEhrlichetal., author = {Hoinkes, Carl J. J. and Romano, Marco and Ehrlich, Ingo and H{\"o}cherl, Johannes and Gebbeken, Norbert}, title = {Investigation of fibre reinforced plastics with monolithic and hybrid stacking sequences under high-velocity impact loads}, series = {Applied Research Conference 2014 - ARC 2014, 5th July 2014, Ingolstadt}, booktitle = {Applied Research Conference 2014 - ARC 2014, 5th July 2014, Ingolstadt}, editor = {Ziemann, Olaf and Mottok, J{\"u}rgen and Pforr, Johannes}, publisher = {Shaker}, address = {Aachen}, language = {en} } @inproceedings{EisenriedRomanoJungbaueretal., author = {Eisenried, Michael and Romano, Marco and Jungbauer, Bastian and Ehrlich, Ingo and Gebbeken, Norbert}, title = {Influence of parameters of the production process on the material quality of unidirectionally reinforced prepregs}, series = {Applied Research Conference 2013, ARC 2013 ; 17th and 18th October 2013, Deggendorf}, booktitle = {Applied Research Conference 2013, ARC 2013 ; 17th and 18th October 2013, Deggendorf}, editor = {Ziemann, Olaf and Bogner, Werner and Mottok, J{\"u}rgen}, publisher = {Shaker}, address = {Aachen}, pages = {70 -- 75}, language = {en} } @inproceedings{LindnerBerndtTschurtschenthaletal., author = {Lindner, Matthias and Berndt, Dominik and Tschurtschenthal, Karl and Ehrlich, Ingo and Jungbauer, Bastian and Schreiner, Rupert and Pipa, Andrei V. and Hink, R{\"u}diger and Foest, R{\"u}diger and Brandenburg, Ronny and Neuwirth, Daniel and Karpen, Norbert and Bonaccurso, Elmar and Weichwald, Robert and Max, Alexander and Caspari, Ralf}, title = {Aircraft Icing Mitigation by DBD-based Micro Plasma Actuators}, series = {AIAA AVIATION 2020 FORUM: June 15-19, 2020}, booktitle = {AIAA AVIATION 2020 FORUM: June 15-19, 2020}, doi = {10.2514/6.2020-3243}, abstract = {We present the application of plasma actuators as a technology for ice prevention at airfoils. The miniaturized dielectric barrier discharge (DBD) plasma actuators (PA) were fabricated by means of microelectromechanical systems (MEMS). We elucidate how to make the actuator samples scalable and applicable to any desired shape by the use of flexible inorganic zirconia substrates. For this purpose, we applied our developed embedding method to integrate the micro actuators in modern carbon/glass fiber reinforced polymer (CFRP/GFRP) materials. Next, the embedded actuator samples were mounted on a mechanical air profile-like fixture and placed in the icing wind tunnel iCORE. The samples were tested in rime ice conditions at temperatures of -15 to -20° C and air speeds up to 30 m/s. Unlike other groups we used a thin film zirconia substrate as dielectric for the plasma actuator. Due to the low substrate thickness of just 150 µm, an operating voltage of 2 kVRMS is already sufficient enough for a stable plasma formation. The experiments show that the operated actuator was able to prevent the ice formation and first indications of a De-icing function were also found. Hence, we show that it is feasible to realize an anti-icing system with zirconia-based plasma actuators operated at lower voltages compared to conventional ones.}, language = {en} } @inproceedings{LindnerBerndtJungbaueretal., author = {Lindner, Matthias and Berndt, Dominik and Jungbauer, Bastian and Ehrlich, Ingo and Schreiner, Rupert and Pipa, Andrei V. and Hink, R{\"u}diger and Foest, R{\"u}diger and Brandenburg, Ronny and Max, Alexander and Caspari, Ralf}, title = {Fabrication, surface integration and testing of miniaturized dielectric barrier discharge plasma actuators for active flow control applications}, series = {AIAA Aviation 2019 Forum, 17-21 June 2019, Dallas, Texas}, booktitle = {AIAA Aviation 2019 Forum, 17-21 June 2019, Dallas, Texas}, doi = {10.2514/6.2019-2998}, language = {en} } @inproceedings{NiedernhuberEhrlichHoltmannspoetter, author = {Niedernhuber, Michal and Ehrlich, Ingo and Holtmannsp{\"o}tter, Jens}, title = {Fiber-Oriented Repair of Fiber Reinforced Plastics: Investigations on Tensile Specimens}, series = {4th Applied Research Conference - ARC 2014, 5th July 2014, Ingolstadt}, booktitle = {4th Applied Research Conference - ARC 2014, 5th July 2014, Ingolstadt}, editor = {Ziemann, Olaf and Mottok, J{\"u}rgen and Pforr, Johannes}, publisher = {Shaker}, address = {Aachen}, pages = {298 -- 302}, language = {en} } @inproceedings{PongratzEhrlich, author = {Pongratz, Christian and Ehrlich, Ingo}, title = {Structural Dynamic Analysis of Thin Composite Plates Using Noncontact Measurement and Excitation}, 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}, isbn = {978-3-86460-494-2}, pages = {351 -- 358}, language = {en} } @techreport{PongratzEhrlich, author = {Pongratz, Christian and Ehrlich, Ingo}, title = {DampSIM: Lebensdauer{\"u}berwachung von faserverst{\"a}rkten Kunststoffen auf Basis der strukurdynamischen Werkstoffd{\"a}mpfung}, series = {Forschungsbericht 2017 / Ostbayerische Technische Hochschule Regensburg}, journal = {Forschungsbericht 2017 / Ostbayerische Technische Hochschule Regensburg}, editor = {Baier, Wolfgang}, organization = {Ostbayerische Technische Hochschule Regensburg}, isbn = {978-3-9818209-3-5}, pages = {62 -- 63}, language = {de} } @techreport{PongratzEhrlich, author = {Pongratz, Christian and Ehrlich, Ingo}, title = {High-End-Strukturen f{\"u}r den Leichtbau - mit faserverst{\"a}rktem 3D-Druck}, series = {Forschung 2018 / Ostbayerische Technische Hochschule Regensburg}, journal = {Forschung 2018 / Ostbayerische Technische Hochschule Regensburg}, editor = {Baier, Wolfgang}, organization = {Ostbayerische Technische Hochschule Regensburg}, isbn = {978-3-9818209-4-2}, pages = {64 -- 65}, language = {de} } @misc{JudenmannPongratzEhrlichetal., author = {Judenmann, Anna and Pongratz, Christian and Ehrlich, Ingo and H{\"o}fer, Philipp and Holtmannsp{\"o}tter, Jens}, title = {Additive Fertigung von endlosfaserverst{\"a}rkten Kunststoffstrukturen}, series = {M{\"u}nchner Leichtbauseminar 2022, 26. October 2022, 16. November 2022, 30 November 2022, Munich/Neubiberg/Garching}, journal = {M{\"u}nchner Leichtbauseminar 2022, 26. October 2022, 16. November 2022, 30 November 2022, Munich/Neubiberg/Garching}, abstract = {Additive Fertigung hat sich in zahlreichen industriellen Anwendungen etabliert und bildet eine wichtige Schl{\"u}sseltechnologie. Im Gegensatz zu metallischen Werkstoffen, haben additiv gefertigte Bauteile aus Kunststoffen geringere Festigkeit und Steifigkeit, sodass sich ihre Verwendung als lasttragende Strukturen schwierig gestaltet. Insbesondere der Einsatz von endlosen Verst{\"a}rkungsfasern kann die mechanischen Eigenschaften additiv gefertigter Strukturen signifikant verbessern und die Fertigung hochbelastbarer Faserverbundstrukturen im 3D-Druckverfahren erm{\"o}glichen. Daher gilt es aktuell notwendige Anlagen und Prozessketten f{\"u}r den Fertigungsprozess aber auch Vorgehensweisen f{\"u}r die belastungsoptimierte Auslegung der Faserverl{\"a}ufe innerhalb des Bauteils zu entwickeln, um so das Themengebiet „Endlosfaserverst{\"a}rkter 3D-Druck" weiter voranzutreiben. F{\"u}r mehr r{\"a}umliche Freiheit bei der Positionierung der Druckbahnen k{\"o}nnen industrieroboterbasierte Systeme eingesetzt werden, um so das Potenzial gerichteter Bauweise von Faserverbundstrukturen auch im additiven Fertigungsprozess vollumf{\"a}nglich aussch{\"o}pfen zu k{\"o}nnen. Dabei erm{\"o}glicht ihr Einsatz auch eine r{\"a}umliche Ablage der Faserverst{\"a}rkung, wobei f{\"u}r die Materialablage ein geeigneter 3D-Druckkopf erforderlich ist. F{\"u}r die Implementierung der Faserverst{\"a}rkung ist zudem eine dem Lastfall entsprechende Auslegung des Bauteils sowie die Ermittlung einer sinnvollen Faserpositionierung innerhalb des Bauteils erforderlich, wobei unterschiedliche Variablen aus den Bereichen Material, Struktur und Fertigungsprozess ber{\"u}cksichtigt werden m{\"u}ssen. Im Rahmen des Vortrages werden die Herausforderungen der Technologieentwicklung des endlosfaserverst{\"a}rkten 3D-Drucks aufgegriffen sowie auf eine belastungsorientierte Faserpositionierung n{\"a}her eingegangen. Aktuelle Erkenntnisse werden diskutiert sowie eine Entwurfsmethodik f{\"u}r die Prozesspfadgenerierung vorgeschlagen.}, language = {de} } @misc{OlbrichPongratzBierletal., author = {Olbrich, Florian and Pongratz, Christian and Bierl, Rudolf and Ehrlich, Ingo}, title = {Method and System for Evaluating a Structural Integrity of an Aerial Vehicle}, series = {Europ{\"a}isches Patentblatt (09.12.2020) zur Anmeldung: OTH Regensburg, Anmeldenummer: 19179054.2, Patentnummer 1001/3748327, Ver{\"o}ffentlichungsnummer: 3 748 327}, journal = {Europ{\"a}isches Patentblatt (09.12.2020) zur Anmeldung: OTH Regensburg, Anmeldenummer: 19179054.2, Patentnummer 1001/3748327, Ver{\"o}ffentlichungsnummer: 3 748 327}, pages = {395 -- 396}, language = {en} } @article{NiedernhuberHoltmannspoetterEhrlich, author = {Niedernhuber, Michal and Holtmannsp{\"o}tter, Jens and Ehrlich, Ingo}, title = {Fiber-oriented repair geometries for composite materials}, series = {Composites, Part B}, volume = {94}, journal = {Composites, Part B}, doi = {10.1016/j.compositesb.2016.03.027}, pages = {327 -- 337}, abstract = {In this paper, the idea of fiber-oriented repair geometries for carbon fiber reinforced plastics (CFRP) is investigated. It considers the differing mechanical properties of unidirectional fiber reinforced material by excluding overlapping regions perpendicular to the fiber direction of the particular layer. A mechanical and numerical comparison of tensile strength of stepped joints with continuous step lengths per ply and stepped joints with reduced step lengths in plies with fiber orientation differing from load direction is performed. Finite element simulations show similar shear stresses. Mechanical tests of CFRP laminates with stepped joints show no significant deviation in tensile strength, in spite of a joint length reduction of nearly 40\%. This leads to the possibility of a significant reduction of repair area.}, language = {en} } @article{PongratzSchlampJungbaueretal., author = {Pongratz, Christian and Schlamp, Matthias and Jungbauer, Bastian and Ehrlich, Ingo and Petratos, P. and Mourtos, N.}, title = {Detection of Delamination Damages in Thin Composite Plates using Noncontact Measurement of Structural Dynamic Behavior}, series = {Athens Journal of Technology \& Engineering}, volume = {3}, journal = {Athens Journal of Technology \& Engineering}, number = {4}, doi = {10.30958/AJTE.3-4-3}, pages = {315 -- 331}, language = {en} } @misc{OlbrichPongratzBierletal., author = {Olbrich, Florian and Pongratz, Christian and Bierl, Rudolf and Ehrlich, Ingo}, title = {Method and System for Evaluating a Structural Integrity of an Aerial Vehicle}, language = {en} } @article{GebhardtSchlampEhrlichetal., author = {Gebhardt, Jakob and Schlamp, Matthias and Ehrlich, Ingo and Hiermaier, Stefan}, title = {Low-velocity impact behavior of elliptic curved composite structures}, series = {International Journal of Impact Engineering}, volume = {180}, journal = {International Journal of Impact Engineering}, publisher = {Elsevier}, doi = {10.1016/j.ijimpeng.2023.104663}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-59304}, pages = {8}, abstract = {Although many composite structures are inconsistently curved, such as the leading edges of aircraft wings, the variety of research in impact engineering is almost limited to the impact performance of plates or cylindrically curved specimens. It is not known whether the findings obtained from standardized tests can be transferred to curved structures or which adaptions are required. Therefore, a deeper understanding of the deformation and damage behavior of inconsistently curved structures is essential to transfer the observed impact behavior of flat specimens to general curved structures and therefore to utilize the full lightweight potential of a load-specific design. An accurate description of the procedure as well as the results of the experimental and numerical study of the low-velocity impact behavior of differently single-curved elliptic specimens is presented. To close the research gap of the impact behavior of geometries with curvatures between the plates and simplified leading edges, novel specimens geometries have been derived from established impact test standards. Glassfiber-reinforced specimens are subjected to an instrumented impact test at constant impact energy. This is numerically investigated by a stacked-layer model, which used cohesive zone modeling to enable the simulation of matrix cracking, fiber fracture and delamination. The resulting projected damage areas, as well as the force and deflection histories, were evaluated and section cuts were examined to discuss the damage morphology, formation and propagation process. Significant effects on maximum deflection, compliance and dynamic behavior on the size and morphology of damage were found.}, language = {en} } @misc{SchimmerGebhardtMotschEichmannetal., author = {Schimmer, Florian and Gebhardt, Jakob and Motsch-Eichmann, N. and Hausmann, Joachim M. and Ehrlich, Ingo}, title = {The effect of curvature on the low-velocity impact resistance of CF/PEEK laminates}, series = {30 Years IVW Anniversary Colloquium, Leibnitz-Institut f{\"u}r Verbundwerkstoffe Kaiserslautern, 2021}, journal = {30 Years IVW Anniversary Colloquium, Leibnitz-Institut f{\"u}r Verbundwerkstoffe Kaiserslautern, 2021}, language = {en} } @article{AfanasevHoeferHoltmannspoetteretal., author = {Afanasev, Anna and H{\"o}fer, Philipp and Holtmannsp{\"o}tter, Jens and Zimmer, Felix and Ehrlich, Ingo}, title = {Development of a continuous fiber-reinforced 3D printing process with a 6-axis robot arm: Process design and equipment}, series = {The International Journal of Advanced Manufacturing Technology}, journal = {The International Journal of Advanced Manufacturing Technology}, publisher = {Springer}, issn = {0268-3768}, doi = {10.1007/s00170-025-17263-3}, pages = {20}, abstract = {The utilisation of 3D printing processes in the fabrication of continuous fiber-reinforced composites confers a multitude of advantages, in particular flexible design based on structural requirements. In order to achieve greater flexibility, there is a necessity for 3D printing systems that allow for customisable material selection and fiber positioning. This paper presents the design of a robot-based 3D printing system that incorporates an in-situ impregnation line and flexibility regarding the machine code generation for fiber positioning. The development of the system enabled the attainment of an average fiber volume content of up to 37.12\%. In the tensile tests, material characteristics up to E1 = 24.7 GPa and strength of up to RM1 = 0.51 GPa were determined.}, language = {en} }