TY - CHAP A1 - Schmid, Vinzent A1 - Jungbauer, Bastian A1 - Romano, Marco A1 - Ehrlich, Ingo A1 - Gebbeken, Norbert ED - Mottok, Jürgen ED - Ziemann, Olaf T1 - Diminution of mass of different types of fibre reinforcements due to thermal load T2 - Applied Research Conference 2012 - ARC 2012, 25./26. June 2012 Y1 - 2012 SP - 231 EP - 235 PB - Shaker ER - TY - CHAP A1 - Bohmann, T. A1 - Schlamp, Matthias A1 - Ehrlich, Ingo ED - Klippel, Clemens ED - Mottok, Jürgen ED - Reichenberger, Marcus T1 - Analysis of the Acoustic Emission Failure Frequencies of Glass Fiber Reinforced Composite Components T2 - Applied Research Conference 2017 - ARC, 7 July 2017, München Y1 - 2017 SP - 369 EP - 373 PB - Book-on-demand Verlag CY - Norderstedt ER - TY - CHAP A1 - Schmid, Vinzent A1 - Bruland, Matthias A1 - Ehrlich, Ingo A1 - Kastenmeier, Andreas ED - Rahman, Jamal ED - Heinze, Ronald T1 - Entwicklung und Regelung eines hydraulischen Biegeprüfstands T2 - Virtuelle Instrumente in der Praxis 2015 - Begleitband zum 20. VIP-Kongress. Y1 - 2015 PB - VDE-Verlag CY - Berlin/Offenbach ER - TY - CHAP A1 - Nübler, S. A1 - Schmid, Vinzent A1 - Ehrlich, Ingo ED - Mottok, Jürgen ED - Reichenberger, Marcus ED - Stolle, Reinhard T1 - FEM-Simulation of a Tube to Flange Joint under Bending Load T2 - Applied Research Conference 2016 - ARC 2016, Augsburg, 24 June 2016 Y1 - 2016 PB - Pro Business Verlag CY - Berlin ER - TY - CHAP A1 - Romano, Marco A1 - Micklitz, Matthias A1 - Olbrich, Florian A1 - Bierl, Rudolf A1 - Ehrlich, Ingo A1 - Gebbeken, Norbert T1 - Experimental investigation of damping properties of unidirectionally and fabric reinforces plastics by the free decay method T2 - Proceeding of the 15th International Materials Symposium (IMSP´2014), Pamukkale University (Denizli, Turkey), 15./17. October 2014 Y1 - 2014 SP - 665 EP - 679 ER - TY - JOUR A1 - Romano, Marco A1 - Eisenried, Michael A1 - Jungbauer, Bastian A1 - Ehrlich, Ingo A1 - Gebbeken, Norbert T1 - Influence of parameters of the production process on the material quality of unidirectionally reinforced prepregs JF - Journal of Achievements in Materials and Manufacturing Engineering (JAMME) N2 - Purpose: A prepreg production device in laboratory scale is used to develop the production process of unidirectionally reinforced prepregs. Design/methodology/approach: The aim of the prepreg production device is to impregnate different types of reinforcement fibers with an arbitrarily selectable thermoset matrix system that completely satisfies the requirements for autoclave processing. As the prepreg production device is designed and built up modularly every module corresponds one step in the process. Findings: To identify the parameters of the production process and investigate its sensitivity on the material quality of both the prepreg as an uncured semi-finished product and the composite as the cured material experimental investigations regarding the resin flow, fiber volume content, mass per unit area and void content are carried out. Overall four material combinations have been investigated, where in each case the selected impregnation temperature and the width of the impregnation gap has been reproducibly varied in selected steps. Research limitations/implications: The experimental characterization of the prepregs and of the composite material is carried out according to German standards. Y1 - 2015 UR - http://jamme.acmsse.h2.pl/vol68_1/6815.pdf VL - 68 IS - 1 SP - 32 EP - 44 ER - TY - JOUR A1 - Romano, Marco A1 - Ehrlich, Ingo A1 - Gebbeken, Norbert T1 - Parametric characterization of a mesomechanic kinematic caused by ondulation in fabric reinforced composites: analytical and numerical investigations JF - Frattura ed Integrità Strutturale (Fracture and Structural Integrity) N2 - A parametric characterization of a mesomechanic kinematic caused by ondulation in fabric reinforced composites is investigated by analytical and numerical investigations. Due to the definition of plain representative sequences of balanced plain-weave fabric reinforced single layers based on sines the variable geometric parameters are the amplitude and the length of the ondulation. The mesomechanic kinematic can be observed in both the analytic model and the FE-analyses. The analytic model yields hyperbolic correlations due to the strongly simplifying presumptions that neglect elasticity. In contrast the FE-analyses yield linear correlations in much smaller amounts due to the consideration of elastic parts, yet distinctly. Y1 - 2017 U6 - https://doi.org/10.3221/IGF-ESIS.39.22 VL - 11 IS - 39 SP - 226 EP - 247 ER - TY - JOUR A1 - Romano, Marco A1 - Ehrlich, Ingo T1 - Classification of damping properties of fabric-reinforced flat beam-like specimens by a degree of ondulation implying a mesomechanic kinematic JF - Science and Engineering of Composite Materials N2 - In order to determine the influence of the ondulations in fabrics on the damping properties of fiber-reinforced plastics, the structural dynamic properties of fabric- and unidirectionally reinforced plastics are investigated. The free decay behavior of flat beam-like specimens is investigated under fixed-free boundary conditions. As the material damping is consistently higher in fabric-reinforced specimens compared to unidirectionally reinforced ones, a contribution of an additionally acting mesomechanic kinematic in fabric weaves is implied. Based on a degree of ondulation, it is possible to classify the enhancement of the material damping and determine the corresponding energy dissipation. The study provides valuable quantitative relations of the additional damping effect due to the mesomechanic kinematic. Compared to the unidirectionally reinforced material, plain weave enhances the material damping by 37…52% at ˜OPL=0.0133 , whereas twill weave 2/2 enhances it by 31…40% at ˜OT2=0.0098 . The consideration of the findings contributes to a deeper understanding of the visco-elastic dynamic behavior of fabric-reinforced plastics and allows further applications in research, development, and industry. KW - fiber-reinforced plastics KW - mesomechanic scale KW - fabric-reinforced layer KW - ondulation Y1 - 2024 U6 - https://doi.org/10.1515/secm-2024-0019 SN - 2191-0359 SN - 0792-1233 N1 - Corresponding author der OTH Regensburg: Marco Romano VL - 31 IS - 1 PB - Walter de Gruyter GmbH ER - TY - JOUR A1 - Kastenmeier, Andreas A1 - Schmid, Vinzent A1 - Ehrlich, Ingo A1 - Petratos, P. A1 - Mourtos, N. A1 - Trafalis, T. T1 - Specimen Preparation and Material Characterization of Filament Wound GFRP Composite Tubes JF - Athens Journal of Technology & Engineering N2 - Filament wound composite structures are widely used in the field of pressure vessels, tubes, pipelines or rocket cases. The mechanical behavior of these structures is typically different from those of flat laminated structures due to an alternating lay-up sequence, winding tension and manufacturing induced imperfections. However, design and analysis issues require the same engineering data as used for laminated structures in general. It has therefore become necessary to establish an accompanying quality assurance procedure following the production process to identify the material properties of the manufactured tubes especially for the single layer. Consequently, there are three different approaches of determining the elastic moduli and tensile strengths of a filament wound laminate. Either specimens are resected from a curved tube, from a tube with plane areas or standardized flat specimens are manufactured under deviating production conditions. All approaches entail disadvantages, whether in terms of manufacturing or testing parameters including geometry, lay-up sequence, porosity, fiber tension and load direction. This study presents the discrepancies in the determination of mechanical properties of a filament wound glass-fiber-reinforced polymer tube on curved or cylindrical specimens and flat specimens produced to meet the specifications of international standards. In order to obtain material properties not only in longitudinal but also in transverse direction of the tubes, the so-called split-disk tensile test modeled after ASTM Standard D 2290, is used with tube segments.The procedures of specimen production and preparation are described in detail. Material properties such as the fiber volume and void content of the composite specimens are conducted in order to consider quality and production differences. Finally tensile tests are performed and the results are compared and discussed. KW - Composite KW - Fiber-reinforced polymer KW - Filament winding KW - Split-disk KW - Tensile tests KW - Tubes Y1 - 2017 UR - https://www.athensjournals.gr/technology/2017-4-3-2-Kastenmeier.pdf VL - 4 IS - 3 SP - 191 EP - 205 ER - TY - CHAP A1 - Ottawa, Patrycja A1 - Romano, Marco A1 - Ehrlich, Ingo A1 - Wagner, Marcus A1 - Gebbeken, Norbert T1 - The influence of ondulation in fabric reinforced composites on dynamic properties in a mesoscopic scale T2 - 11. LS-DYNA Forum, 9. - 10. Oktober 2012, Ulm N2 - Structural mechanic properties of fiber reinforced plastics depend on the single components’ properties, namely matrix and fiber [5]. Simple micromechanic homogenization theories reach a limit when a laminate consists of fabric reinforced layers instead of unidirectional layers. The ondulations of warp and fill yarn caused by the textile semi-finished product are the reason why the mesoscopic scale, which is in between the microscopic and the macroscopic scale, has to be taken into account when mechanically characterizing fabric reinforced composites [3]. In this scale a mesomechanic kinematic can be derived analytically. Especially, when considering free damped vibrations of structures the repeated acting of the kinematic correlation significantly affects the damping behaviour to higher values compared to theoretically predicted damping ratios. The model is investigated using Finite-Element-Analyses and basically validated experimentally. Y1 - 2012 UR - https://www.dynamore.de/de/download/papers/dynamore/de/download/papers/ls-dyna-forum-2012/documents/materials-5-2 SP - 171 EP - 172 ER - TY - THES A1 - Romano, Marco T1 - Charakterisierung von gewebeverstärkten Einzellagen aus kohlenstofffaserverstärktem Kunststoff (CFK) mit Hilfe einer mesomechanischen Kinematik sowie strukturdynamischen Versuchen N2 - Die vorliegende Arbeit behandelt die analytische und numerische Identifikation einer mesomechanischen Kinematik in gewebeverstärkten Einzellagen sowie deren Validierung über die Strukturdynamik von flachen stabförmigen Probekörpern aus kohlenstofffaserverstärktem Kunststoff (CFK). Unter der Voraussetzung, dass das wiederholte Wirken der Kinematik Energie dissipiert, trägt sie bei zyklischer viskoelastischer Deformation zusätzlich zur reinen viskoelastischen Werkstoffdämpfung in gewebeverstärkten Einzellagen bei. Die analytischen und numerischen Untersuchungen beschränken sich auf die Betrachtung des ebenen, zweidimensionalen Zusammenhangs einer vollständigen Ondulation bzw. einer repräsentativen Sequenz in Dickenrichtung. Zur Parameteridentifikation werden die geometrischen Abmessungen in definierten Schritten variiert. Dafür wird der Grad der Ondulation in gewebeverstärkten Einzellagen Õ=A/L als dimensionslose Kennzahl eingeführt. Zur Validierung der dämpfungserhöhenden Wirkung der in den analytischen und numerischen Untersuchung identifizierten mesomechanischen Kinematik in gewebeverstärkten Einzellagen werden in experimentellen strukturdynamischen Untersuchungen frei abklingende Transversalschwingungen von einseitig fest eingespannten Probekörpern untersucht. Im Detail werden flache stabförmige Probekörper aus kohlenstofffaserverstärktem Epoxidharz mit Lagenaufbauten aus 0°-unidirektionalen und gewebeverstärkten Einzellagen untersucht. Die Ergebnisse der experimentellen strukturdynamischen Untersuchungen dienen schließlich der Validierung des analytischen Modells und der numerischen Berechnungen. Die dämpfungserhöhende Wirkung der identifizierten mesomechanischen Kinematik wird schließlich in Abhängigkeit des eingeführten Grades der Ondulation Õ quantifiziert. KW - faserverstärkte Kunststoffe KW - CFK KW - Mesomechanik KW - Leinwandgewebe KW - Köpergewebe 2/2 KW - Ondulation KW - Grad der Ondulation KW - Strukturdynamik KW - Dämpfung KW - Werkstoffdämpfung; KW - flache stabförmige Probekörper KW - Kragbalken Y1 - 2017 SN - 978-3-8440-5177-3 U6 - https://doi.org/10.2370/9783844051773 PB - Shaker CY - Aachen ER - TY - JOUR A1 - Bohmann, T. A1 - Schlamp, Matthias A1 - Ehrlich, Ingo T1 - Acoustic emission of material damages in glass fibre-reinforced plastics JF - Composites Part B: Engineering N2 - The aim of this study is to compare two different standardized testing procedures, tensile testing and Mode-I double cantilever beam (DCB) testing, to evaluate a possible correlation between the dominant failure in glass fibre-reinforced plastics and their according acoustic emissions (AE). AE is processed by using a burst collection of all recorded transient signals and is further analysed with the k-means clustering algorithm. To generate damage related AE, a series of experiments for tensile testing and Mode-I DCB testing is performed on 16-layer glass fibre/epoxy specimens with a cross-ply lay-up for tensile and an unidirectional lay-up for Mode-I DCB testing. Three sensors at tensile testing and one sensor at Mode-I DCB testing gather AE data. The results of clustered burst signals show a good accordance between both testing procedures, with a similar weighted peak frequency (WPF) range in each classified cluster. In total, three different clusters are determined. An assignment of these three clusters to the three dominant damage mechanisms, visually observed by microscopy, is suggested. Y1 - 2018 U6 - https://doi.org/10.1016/j.compositesb.2018.09.018 VL - 155 IS - December SP - 444 EP - 451 PB - Elsevier ER - TY - RPRT A1 - Valentino, Piergiorgio A1 - Romano, Marco A1 - Ehrlich, Ingo A1 - Furgiuele, Franco A1 - Gebbeken, Norbert T1 - Mechanische Charakterisierung von basaltfaser-verstärkten Kunststoffen mit Gewebeverstärkung – Numerische und experimentelle Untersuchungen T2 - Forschungsbericht 2013 Y1 - 2014 UR - https://doi.org/10.35096/othr/pub-799 PB - inixmedia GmbH Marketing & Medienberatung ER - TY - CHAP A1 - Afanasev, Anna ED - Mottok, Jürgen ED - Reichenberger, Marcus T1 - Force-oriented 3D printing of continuous fiber-reinforced plastic structures T2 - Applied Research Conference 2019 - ARC 2019, 08 July 2019, Regensburg KW - Faserverbundwerkstoff KW - 3D-Druck Y1 - 2019 SN - 978-3-96409-182-6 SP - 213 EP - 218 PB - Pro Business GmbH CY - Berlin ER - TY - CHAP A1 - Baumer, A. A1 - Kastenmeier, Andreas A1 - Ehrlich, Ingo ED - Ziemann, Olaf ED - Mottok, Jürgen ED - Pforr, Johannes T1 - Investigation of Bolted Composite Joints with Different Reinforcement Elements at the Bolt Hole T2 - 4th Applied Research Conference, 5th July 2014, Ingolstadt Y1 - 2014 SP - 255 EP - 258 PB - Shaker ER - TY - CHAP A1 - Fritz, B. A1 - Schmid, Vinzent A1 - Ehrlich, Ingo ED - Ziemann, Olaf ED - Mottok, Jürgen ED - Pforr, Johannes T1 - Analytical and numerical shear stress analysis of adhesive structural bonded joints under tension load T2 - Applied Research Conference 2014 - ARC 2014, 5th July 2014, Ingolstadt Y1 - 2014 SP - 266 EP - 271 PB - Shaker CY - Aachen ER - TY - CHAP A1 - Baumer, A. A1 - Kastenmeier, Andreas A1 - Ehrlich, Ingo ED - Mottok, Jürgen ED - Reichenberger, Marcus ED - Scharfenberg, J. ED - Ziemann, Olaf T1 - A Numerical Study of Reinforced Bolted Composite Joints T2 - Applied Research Conference 2015: ARC 2015 - Nürnberg, 3rd July 2015 Y1 - 2015 SP - 278 EP - 282 PB - Book-on-demand-Verlag ER - TY - CHAP A1 - Wätzig, A. A1 - Schmid, Vinzent A1 - Ehrlich, Ingo ED - Mottok, Jürgen ED - Reichenberger, Marcus ED - Stolle, Reinhard T1 - Damage Modelling of Adhesive Joints Using the Cohesive Zone Model T2 - Applied Research Conference 2016 - ARC 2016, Augsburg, 24 June 2016 Y1 - 2016 PB - Pro Business Verlag CY - Berlin ER - TY - CHAP A1 - Dinnebier, Heinrich A1 - Ehrlich, Ingo ED - Meran, C. T1 - The Effects of Severe Temperature Changes and High Humidity on Porous CFRP T2 - Proceedings of the 15th International Materials Symposium (IMSP´2014), Pamukkale University (Denizli, Turkey), 15./17. October 2014 N2 - 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. Y1 - 2014 UR - http://jamme.acmsse.h2.pl/vol67_1/6712.pdf SP - 433 EP - 440 ER - TY - CHAP A1 - Ehrlich, Ingo A1 - Dinnebier, Heinrich A1 - Jost, C. ED - Meran, C. T1 - Comparison of Impact Delaminations in CFRP Using Ultrasonic Testing, Microfocus Computed X-Ray Tomography and Micrographic Cross-Section T2 - Proceeding of the 15th International Materials Symposium (IMSP´2014), Pamukkale University (Denizli, Turkey), 15./17. October 2014 Y1 - 2014 SP - 441 EP - 450 ER - TY - CHAP A1 - Wenzl, C. ED - Mottok, Jürgen ED - Reichenberger, Marcus ED - Bogner, Werner T1 - Comparison of Analytical and Numerical Results for the Deformation of Circular Curved Structures under Pressure Load T2 - Applied Research Conference 2018 - ARC 2018, 10 July 2018 Deggendorf Y1 - 2018 SN - 978-3-96409-018-8 SP - 150 EP - 155 PB - Pro Business GmbH CY - Berlin ER - TY - CHAP A1 - Faber, M. A1 - Kastenmeier, Andreas A1 - Ehrlich, Ingo ED - Mottok, Jürgen ED - Reichenberger, Marcus ED - Stolle, Reinhard T1 - Three-dimensional finite element analysis of a composite tube with multi-row bolted joints T2 - Applied Research Conference 2016 - ARC 2016, Augsburg, 24 June 2016 Y1 - 2016 PB - Pro Business Verlag CY - Berlin ER - TY - CHAP A1 - Gebhardt, Jakob ED - Mottok, Jürgen ED - Reichenberger, Marcus ED - Bogner, Werner T1 - Low Velocity Impact of GFRP Laminate – Experimental Observations and Numerical Modelling T2 - Applied Research Conference 2018 - ARC 2018, 10 July 2018 Deggendorf Y1 - 2018 SN - 978-3-96409-018-8 SP - 211 EP - 215 PB - Pro Business GmbH CY - Berlin ER - TY - CHAP A1 - Ibanez Gomez, D. A1 - Kastenmeier, Andreas A1 - Ehrlich, Ingo ED - Ziemann, Olaf ED - Mottok, Jürgen ED - Pforr, Johannes T1 - Development and construction of a winding machine for the production of composite tubes T2 - 4th Applied Research Conference - ARC 2014, 5th July 2014, Ingolstadt Y1 - 2014 SP - 315 EP - 318 PB - Shaker CY - Aachen ER - TY - CHAP A1 - Bruland, Matthias A1 - Schmid, Vinzent A1 - Ehrlich, Ingo ED - Ziemann, Olaf ED - Mottok, Jürgen ED - Pforr, Johannes T1 - Analyzing and Testing of a Single Solution of Self-cutting Thread Inserts in Composites T2 - Applied Research Conference 2014 - ARC 2014, 5th July 2014, Ingolstadt Y1 - 2014 SP - 286 EP - 288 PB - Shaker ER - TY - JOUR A1 - Schimmer, Florian A1 - Ladewig, Sven A1 - Motsch, Nicole A1 - Hausmann, Joachim M. A1 - Ehrlich, Ingo T1 - Comparison of Low-Velocity Impact Damage Behavior of Unidirectional Carbon Fiber-Reinforced Thermoset and Thermoplastic Composites JF - Key Engineering Materials N2 - 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. KW - Barely Visible Impact Damage KW - Carbon Fiber Reinforced Plastic KW - Low-velocity-impact KW - Thermoplastics KW - Ultrasonic Analysis Y1 - 2019 U6 - https://doi.org/10.4028/www.scientific.net/KEM.809.9 SN - 1662-9795 VL - 809 SP - 9 EP - 14 PB - Trans Tech Publications ER - TY - CHAP A1 - Siegl, Marco A1 - Rieger, David A1 - Kovárík, Tomáš A1 - Ehrlich, Ingo T1 - Long-Term Behavior of Thermoplastics under UV Light tested by a self-build Device T2 - 3. OTH-Clusterkonferenz, 13. April 2018, Weiden, Tagungsband; Festschrift, 5 Jahre OTH-Verbund N2 - 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. Y1 - 2018 UR - https://www.oth-regensburg.de/fileadmin/media/forschung/Dateien_2018/Clusterkonferenz-Tagungsband-2018.pdf SP - 118 EP - 122 ER - TY - CHAP A1 - Valentino, Piergiorgio A1 - Romano, Marco A1 - Ehrlich, Ingo A1 - Furgiuele, Franco A1 - Gebbeken, Norbert ED - Iacovello, F. ED - Risitano, G. ED - Susmel, L. T1 - Mechanical characterization of basalt fibre reinforced plastic with different fabric reinforcements – Tensile tests and FE-calculations with representative volume elements (RVEs) T2 - Acta Fracturae - XXll Convegno Nazionale IGF (Italiano Gruppo Frattura) N2 - 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. Y1 - 2013 UR - http://www.gruppofrattura.it/pdf/convegni/22/IGFXXII/index.html#/242/ ER - TY - CHAP A1 - Seppenhauser, P. ED - Mottok, Jürgen ED - Reichenberger, Marcus T1 - Examinations of the Printer Head Prototype for UV Resins with Continous Fiber-Reinforcement T2 - Applied Research Conference 2019 - ARC 2019, 8 July 2019, Regensburg KW - 3D-Druck KW - Druckkopf KW - Kunstharz KW - Faserverstärkter Kunststoff Y1 - 2019 SN - 978-3-96409-182-6 SP - 241 EP - 248 PB - Pro Business GmbH CY - Berlin ER - TY - JOUR A1 - Micklitz, Matthias A1 - Romano, Marco A1 - Ehrlich, Ingo A1 - Gebbeken, Norbert ED - Ziemann, Olaf ED - Mottok, Jürgen ED - Pforr, Johannes T1 - The influence of ondulations in fabric reinforced layers on the damping properties of fibre-reinforced plastics JF - Applied Research Conference 2014 - ARC 2014, 5th July 2014, Ingolstadt Y1 - 2014 SP - 306 EP - 310 PB - Shaker CY - Aachen ER - TY - CHAP A1 - Niebauer, M. A1 - Schmid, Vinzent A1 - Ehrlich, Ingo ED - Mottok, Jürgen ED - Reichenberger, Marcus ED - Scharfenberg, J. ED - Ziemann, Olaf T1 - Failure Criteria of Adhesively Bonded Joints BT - A Review T2 - Applied Research Conference 2015 - ARC 2015, Nürnberg, 3rd July 2015 - 16. Juli 2015 Y1 - 2015 SN - 978-3863869458 SP - 347 EP - 351 PB - Pro Business Verlag CY - Berlin ER - TY - JOUR A1 - Dinnebier, Heinrich A1 - Ehrlich, Ingo T1 - The effects of severe temperature changes and high humidity on porous CFRP JF - Journal of Achievements in Materials and Manufacturing Engineering (JAMME) N2 - 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. Y1 - 2014 VL - 67 IS - 1 SP - 14 EP - 20 ER - TY - RPRT A1 - Eisenried, Michael A1 - Romano, Marco A1 - Jungbauer, Bastian A1 - Ehrlich, Ingo A1 - Gebbeken, Norbert T1 - Herstellung von unidirektional verstärkten Prepregs im Labormaßstab – Einfluss von Fertigungsparametern auf die Materialqualität T2 - Forschungsbericht 2013 / Ostbayerische Technische Hochschule Regensburg Y1 - 2013 UR - https://doi.org/10.35096/othr/pub-799 SP - 51 EP - 52 CY - Regensburg ER - TY - THES A1 - Ehrlich, Ingo T1 - Impactverhalten schwach gekrümmter Strukturen aus faserverstärkten Kunststoffen Y1 - 2004 UR - https://d-nb.info/973886102/34 CY - München ER - TY - JOUR A1 - Bode, J. A1 - Ehrlich, Ingo T1 - Entwicklung eines finiten Elements für Sandwichanwendungen JF - Zeitschrift für Angewandte Mathematik und Mechanik (ZAMM), Journal of Applied Mathematics and Mechanics Y1 - 1997 VL - 77 IS - 1 SP - 41 EP - 42 ER - TY - JOUR A1 - Romano, Marco A1 - Hoinkes, Carl J. J. A1 - Ehrlich, Ingo A1 - Höcherl, Johannes A1 - Gebbeken, Norbert T1 - Experimental investigation of energy dissipation properties of fibre reinforced plastics with hybrid layups under high-velocity impact loads JF - Journal of Achievements in Materials and Manufacturing Engineering (JAMME) N2 - 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. Y1 - 2014 VL - 64 IS - 1 SP - 14 EP - 20 ER - TY - JOUR A1 - Siegl, Marco A1 - Ehrlich, Ingo T1 - 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 JF - Athens Journal of Technology & Engineering N2 - 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. KW - Bending model KW - Cylindrical coordinate system KW - Fiber-reinforced plastic tubes KW - Permutation of the compliances KW - Transformation of the compliances Y1 - 2017 UR - https://www.athensjournals.gr/technology/2017-4-1-4-Siegl.pdf VL - 4 IS - 1 SP - 47 EP - 62 ER - TY - JOUR A1 - Romano, Marco A1 - Ehrlich, Ingo A1 - Gebbeken, Norbert T1 - Parametric characterization of a mesomechanic kinematic in plain and twill weave 2/2 reinforced composites by FE-calculations JF - Archives of Materials Science and Engineering (ArchivesMSE) N2 - 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. Y1 - 2019 U6 - https://doi.org/10.5604/01.3001.0013.2869 SN - 1897-2764 VL - 97 IS - 1-2 SP - 20 EP - 38 PB - Index Copernicus ER - TY - JOUR A1 - Romano, Marco A1 - Ehrlich, Ingo A1 - Gebbeken, Norbert T1 - Structural mechanic material damping in fabric reinforced composites BT - a review JF - Archives of Materials Science and Engineering (ArchivesMSE) N2 - 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. Y1 - 2017 U6 - https://doi.org/10.5604/01.3001.0010.7747 VL - 88 IS - 1 SP - 12 EP - 41 ER - TY - JOUR A1 - Valentino, Piergiorgio A1 - Sgambitterra, Emanuele A1 - Furgiuele, Franco A1 - Romano, Marco A1 - Ehrlich, Ingo A1 - Gebbeken, Norbert T1 - Mechanical characterization of basalt woven fabric composites BT - numerical and experimental investigation JF - Frattura ed Integrità Strutturale (Fracture and Structural Integrity) N2 - 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. Y1 - 2014 U6 - https://doi.org/10.3221/IGF-ESIS.28.01 VL - 8 IS - 28 SP - 1 EP - 11 ER - TY - RPRT A1 - Schlamp, Matthias A1 - Ehrlich, Ingo ED - Baier, Wolfgang T1 - Analyse des Impact-Verhaltens gekrümmter Strukturbauteile von Luftfahrzeugen zur Entwicklung eines Strukturüberwachungssystems für faserverstärkte Kunststoffe - BIRD T2 - Forschung 2019 / Ostbayerische Technische Hochschule Regensburg N2 - Die in Flugvorausrichtung weisenden Bauteile von Luftfahrzeugen sind oftmals durch Einschläge aufgrund von Vogelschlag, Hagel oder aufgewirbelten Kleinteilen gefährdet. Diese Einschläge, sogenannte Impacts, weisen bei faserverstärkten Kunststoffen ein stark krümmungs- und materialabhängiges Verhalten und Schadensausmaß auf. Impact-Schädigungen führen oftmals zu hohen Reparaturkosten, welche durch eine genauere Kenntnis des Schadens verringert werden können. Zur Klassifizierung dieser Schädigungen steht dabei vor allem das auftretende Frequenz signal des Impacts im Fokus der Untersuchungen. Y1 - 2019 UR - https://doi.org/10.35096/othr/pub-789 SN - 978-3-9818209-6-6 SP - 40 EP - 41 PB - VMK Verlag für Marketing & Kommunikation GmbH & Co. KG ER - TY - JOUR A1 - Romano, Marco A1 - Hoinkes, Carl J. J. A1 - Ehrlich, Ingo A1 - Höcherl, Johannes A1 - Gebbeken, Norbert T1 - Experimental investigation of fibre reinforced plastics with hybrid layups under high-velocity impact loads JF - Frattura ed Integrità Strutturale (Fracture and Structural Integrity) N2 - 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. Y1 - 2014 U6 - https://doi.org/10.3221/IGF-ESIS.29.34 VL - 8 IS - 29 SP - 384 EP - 398 ER - TY - RPRT A1 - Putzer, Michael A1 - Rasmussen, John A1 - Ehrlich, Ingo A1 - Gebbeken, Norbert A1 - Dendorfer, Sebastian ED - Baier, Wolfgang T1 - Muskuloskelettale Simulation zur Untersuchung des Einflusses geometrischer Parameter der Wirbelkörper auf die Belastung der Lendenwirbelsäule T2 - Forschungsbericht 2013 / Ostbayerische Technische Hochschule Regensburg Y1 - 2013 UR - https://doi.org/10.35096/othr/pub-799 SP - 60 EP - 61 CY - Regensburg ER - TY - JOUR A1 - Romano, Marco A1 - Micklitz, Matthias A1 - Olbrich, Florian A1 - Bierl, Rudolf A1 - Ehrlich, Ingo A1 - Gebbeken, Norbert T1 - Experimental investigation of damping properties of unidirectionally and fabric reinforced plastics by the free decay method JF - Journal of Achievements in Materials and Manufacturing Engineering N2 - 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. KW - structural vibration KW - damping KW - fibre reinforced plastics KW - mesomechanic scale KW - fabric reinforced layer Y1 - 2014 VL - 63 IS - 2 SP - 65 EP - 80 ER - TY - RPRT A1 - Siegl, Marco A1 - Ehrlich, Ingo ED - Baier, Wolfgang T1 - Internationale Forschung zum Biege- und Deformationsverhalten von faserverstärkten Kunststoffrohren T2 - Forschung 2019 / OTH Regensburg Y1 - 2019 UR - https://doi.org/10.35096/othr/pub-789 SN - 978-3-9818209-6-6 SP - 42 EP - 43 PB - VMK Verlag für Marketing & Kommunikation ER - TY - RPRT A1 - Siegl, Marco A1 - Ehrlich, Ingo A1 - Siegl, Marco A1 - Ehrlich, Ingo ED - Baier, Wolfgang T1 - Einfluss von Prozessparametern auf die Schmelzimprägnierung zur Herstellung von faserverstärkten Thermoplasten T2 - Forschung 2018 / Ostbayerische Technische Hochschule Regensburg N2 - Die Erforschung von faserverstärkten Kunststoffen (FVK) mit thermoplastischer Matrix ist aufgrund der Schweißeignung als Verbindungstechnologie, der thermischen Umformbarkeit, der Recyclebarkeit sowie der verkürzten Prozesszeiten im Vergleich zu den vorwiegend eingesetzten faserverstärkten Duroplasten erstrebenswert. Die Wechselwirkung zwischen den physikalischen, mechanischen und geometrischen Parametern erhöht den Komplexitätsgrad des Herstellungsprozesses. Ziel ist daher die Entwicklung einer Imprägniertechnik, die eine Fasertränkung mittels eines Thermoplastschmelzbades ermöglicht. Y1 - 2018 UR - https://doi.org/10.35096/othr/pub-1382 SP - 72 EP - 73 PB - VMK Verlag für Marketing & Kommunikation GmbH & Co. KG ER - TY - JOUR A1 - Freese, Jens de A1 - Holtmannspötter, Jens A1 - Raschendorfer, Stefan A1 - Hofmann, Timo T1 - End milling of Carbon Fiber Reinforced Plastics as surface pretreatment for adhesive bonding - effect of intralaminar damages and particle residues JF - The Journal of Adhesion N2 - In this study, the use of dry end milling of carbon fiber reinforced plastics (CFRP) as surface pretreatment for high-strength (structural) adhesive bonding was investigated. Surfaces were pretreated using different milling parameters; subsequently, they were adhesively bonded and tested. In comparison with sanding and other industrial standard pretreatment methods, the measured adhesive strength was significantly lower. Detailed surface investigations utilizing field-emission scanning electron microscopy could identify two major effects for lower adhesion strength. Intralaminar damages and microparticle residues on the created surface reduced the strength of the CFRP adhesive joints. This eventually explains results from investigations on milling pretreated repairs. By application of power ultrasound cleaning equipment and coating with low viscosity epoxy primers, the authors showed a way to overcome the discovered drawbacks and to improve bond strength significantly. Surface roughness measurements showed that the arithmetical mean roughness R(a)can be used as an effective value for assessment of mechanical pretreated CFRP surfaces as well as for the quality of necessarily following cleaning processes. KW - aeronautical KW - BONDED JOINTS KW - butt joints KW - composites KW - epoxides KW - Epoxy KW - GRAPHITE/EPOXY COMPOSITE KW - ORTHOGONAL CUTTING MECHANISMS KW - repair KW - surface treatment Y1 - 2020 U6 - https://doi.org/10.1080/00218464.2018.1557054 VL - 96 IS - 12 SP - 1122 EP - 1140 PB - TAYLOR & FRANCIS ER - TY - CHAP A1 - Judenmann, Anna A1 - Holtmannspötter, Jens A1 - Ehrlich, Ingo T1 - Additive Manufacturing of Continuous Fiber-Reinforced Composites T2 - Proceedings of the Munich Symposium on Lightweight Design 2022 Y1 - 2023 ER - TY - JOUR A1 - Andrae, Matthias A1 - Kastenmeier, Andreas A1 - Gebhardt, Jakob A1 - Ehrlich, Ingo A1 - Gebbeken, Norbert T1 - Shock-tube tests on conventional windows: Exploring retrofit concepts for enhanced blast protection JF - International Journal of Protective Structures N2 - 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. Y1 - 2024 U6 - https://doi.org/10.1177/20414196241284297 SN - 2041-4196 PB - SAGE ER - TY - CHAP A1 - Romano, Marco A1 - Hoinkes, Carl J. J. A1 - Ehrlich, Ingo A1 - Höcherl, Johannes A1 - Gebbeken, Norbert ED - Meran, C. T1 - Influence of the impactor on the experimentally determined energy dissipation properties of fiber-reinforced plastics with hybrid layups under high velocity impact loads T2 - Proceeding of the 15th International Materials Symposium (IMSP´2014), Pamukkale University (Denizli, Turkey), 15./17. October 2014 Y1 - 2014 SP - 650 EP - 664 ER - TY - CHAP A1 - Hoinkes, Carl J. J. A1 - Romano, Marco A1 - Ehrlich, Ingo A1 - Höcherl, Johannes A1 - Gebbeken, Norbert ED - Ziemann, Olaf ED - Mottok, Jürgen ED - Pforr, Johannes T1 - Investigation of fibre reinforced plastics with monolithic and hybrid stacking sequences under high-velocity impact loads T2 - Applied Research Conference 2014 - ARC 2014, 5th July 2014, Ingolstadt Y1 - 2014 PB - Shaker CY - Aachen ER - TY - CHAP A1 - Eisenried, Michael A1 - Romano, Marco A1 - Jungbauer, Bastian A1 - Ehrlich, Ingo A1 - Gebbeken, Norbert ED - Ziemann, Olaf ED - Bogner, Werner ED - Mottok, Jürgen T1 - Influence of parameters of the production process on the material quality of unidirectionally reinforced prepregs T2 - Applied Research Conference 2013, ARC 2013 ; 17th and 18th October 2013, Deggendorf Y1 - 2013 SP - 70 EP - 75 PB - Shaker CY - Aachen ER -