wbk

Jonas Nieschlag, M.Sc.

  • 76131 Karlsruhe
    Kaiserstraße 12

Jonas Nieschlag, M.Sc.

Area of Research:

  • Lightweight manufacturing of fiber reinforced plastics

 

General Tasks:

  • Coordination of the priority program 1712

 

Projects:

 

Test benches:

 

Curriculum Vitae:

since 04/2017 Research Associate at the Institute of Production Science (wbk) at Karlsruhe Institute of Technologie (KIT)
2010-2016 Study of Mechanical and Process Engineering, TU Darmstadt

Publications

[ 1 ] Nieschlag, J.; Ruhland, P.; Daubner, S.; Koch, S. & Fleischer, J. (2018), "Finite element optimisation for rotational moulding with a core to manufacture intrinsic hybrid FRP metal pipes", Production Engineering, vol. 12, no. 2, pp. 239-247. 10.1007/s11740-017-0788-6
Abstract
Lightweight construction is gaining in importance due to increasing demands for energy efficiency. In drive technology, lightweight shafts can for example be produced in a centrifugal process in which dry, hollow fibre preforms are impregnated with polymer resin and cured under rotation. Furthermore, hybrid FRP-metal lightweight shafts can be produced by intrinsically incorporating additional metal load-introducing elements into the process. Due to the nature of the process, the transition between the materials may be conducted in a form-fitting way. So-called centrifugal cores are used for being able to achieve a higher fibre-volume content or produce polygonal profiles with a form fit. The cores made of a silicone-lead compound expand due to the rotational forces. The resulting pressure leads to a good impregnation of the corner areas. Compared to cylindrical centrifugal cores, polygonal ones have a more complex geometry. Designing with FEM is consequently more appropriate. Therefore, this paper shall portray finite element modelling of a polygonal centrifugal core. The challenge of this endeavour constitutes in developing a centrifugal core, which expansion executes a constant impregnation pressure via the profile onto the impregnated fibre layer. For this purpose, the centrifugal core is modelled as an elastic body in ABAQUS. Subsequently, the centrifugal core’s optimum geometry is derived with an optimisation approach. In conclusion, the calculated centrifugal cores are produced in order to be able to manufacture hybrid shafts.

[ 2 ] Nieschlag, J.; Ruhland, P.; Coutandin, S. & Fleischer, J. (2019), "Rotational Molding for the Production of Hybrid FRP Metal Tension and Compression Rods with Form Fit". Konferenzband WGP, eds. Springer.
Abstract
One innovative production process for manufacturing rotationally symmetric FRP-metal components, such as drive shafts or tension and pressure rods, is the rotational molding process. In comparison to common joining processes, such as bonding or screwing, the metallic components and the fiber-reinforced plastic part can be intrinsically joined during the forming process. This saves production time and cost compared to conventional joining processes. In the past, only components with a form fit for radial loads such as polygon shafts have been studied using rotational molding. This paper examines the pro-duction of a hybrid FRP-metal tension and compression rod with an axial form fit. To this end, a production approach will be designed and presented more de-tailedly further below. Furthermore, it is investigated whether the impregnation pressure is sufficient enough to produce hybrid FRP-metal tension and compres-sion rods with good laminate quality and a form fit by rotational molding. To de-termine the quality of the obtained component, computer tomography and micros-copy analyses are conducted.

[ 3 ] Nieschlag, J.; Coutandin, S. & Fleischer, J. (2020), "Production and Tensile Testing of Rotationally Molded Hybrid Composite Tie Rods". SAMPE 2020 Virtual Series | Multifunctional Materials and Structures.
Abstract
An innovative production processes for manufacturing rotationally symmetric FRP-metal components, such as drive shafts or tie rods, is the rotational molding process. In the course of this process, a dry fiber preform and metallic load-introduction elements are inserted into a two-piece mold and subsequently clamped into a spindle. The matrix is injected directly into the rotating mold. Due to the arising centrifugal forces, the preform is impregnated and the component cures under rotation. In comparison to conventional joining processes, such as adhesive bonding or bolt connections, the metallic components as well as the FRP part are intrinsically joined during the forming process. A downstream joining process is not required. The joint is based either on the adhesive property of the matrix system or on a form-fit geometry with undercuts. The paper addresses the production and tensile testing of tie rods. Different rod geometries and different surface treatments, including sandblasting, knurling, and arc spraying, are compared and evaluated.

[ 4 ] Ruhland, P.; Nieschlag, J.; Coutandin, S. & Fleischer, J. (2020), "Wirtschaftliche Herstellung von Leichtbau-Komponenten mittels intrinsischer Hybridisierung", wt Werkstattstechnik online, no. 7, pp. 517-520. 10.37544/1436-4980-2020-07-08-61
Abstract
Hybride Faserverbund-Metall-Bauteile für Anwendungen als Antriebswellen, Achsen oder Zug-Druck-Stangen besitzen aufgrund ihres hohen Leichtbaugrades ein enormes Potential in den unterschiedlichsten Branchen. In diesem Artikel wird das Rotational-Moulding-Verfahren vorgestellt, mit welchem derartige Bauteile schnell und kostengünstig hergestellt werden können.

[ 5 ] Gude, M.; Barfuß, D.; Coutandin, S.; Fleischer, J.; Grützner, R.; Hirsch, F.; Kästner, M.; Müller-Pabel, M.; Müller, R.; Nieschlag, J.; Ruhland, P. & Würfel, V. (2021), "Hybride Hohlstrukturen für Wellen und Streben" in Intrinsische Hybridverbunde für Leichtbautragstrukturen, eds. Fleischer, J., Springer Vieweg, pp. 205-264. ISBN/ISSN: 978-3-662-62832-4
Abstract
Für die Herstellung von leichten Wellen, Rohren, Profilen oder Zug-Druck-Streben werden häufig Hohlstrukturen mit einem geschlossenen Querschnitt eingesetzt, da diese ein günstigeres Verhältnis von Steifigkeit zu Masse aufweisen als entsprechende Vollmaterialvarianten. Im modernen Leichtbau kommen Grundprinzipien zum Einsatz, die sich auch in der Natur wiederfinden lassen. An Orten hoher Belastungen ist oft eine Materialanhäufung und an Orten geringer Belastung eine Materialabnahme zu beobachten. Aus diesem Grund sind in Flora und Fauna dünnwandige Stabprofile bzw. geschlossene rohrförmige Profile weit verbreitete Strukturen. An solchen natürlichen Geometrien lassen sich Leichtbauprinzipien wie die direkte Kraftleitung, die Realisierung eines hohen Widerstandsmomentes und die natürliche Stützwirkung von gekrümmten Strukturen ableiten

[ 6 ] Matkovic, N.; Götz, M.; Kupzik, D.; Nieschlag, J.; Coutandin, S. & Fleischer, J. (2021), "Additives Roboter-Extrusions-System", VDI-Z, vol. 163, pp. 55-57. 10.37544/0042-1766-2021-01-02-55
Abstract
Herkömmliche additive Fertigungsverfahren für Kunststoffbauteile erlauben eine große Designfreiheit, besitzen jedoch Defizite hinsichtlich Fertigungszeit, Bauvolumen und Oberflächenbeschaffenheit. Zur Beseitigung dieser Defizite eignen sich insbesondere flexible Industrieroboter mit druckenden Endeffektoren. Aus diesem Grund wurde am wbk Institut für Produktionstechnik eine vollst?ndige CAE-Prozesskette zur robotergef?hrten Extrusion entwickelt und an einer Anlage erprobt.

[ 7 ] Roth, S.; Nieschlag, J.; Mehner, M.; Coutandin, S. & Fleischer, J. (2021), "Modelling of the temperature distribution of spot-weldable composite/metal joints", Journal of Advanced Joining Processes, 10.1016/j.jajp.2021.100066
Abstract
Resistance spot welding is the most economical joining method for the production of automotive steel bodies. In modern car body construction, however, its future applicability is limited due to the growing mix of materials in multi-material design. In response to increasing weight reduction requirements to protect the environment and natural resources, lightweight materials, and fibre-reinforced plastics (FRP) in particular, are more and more used in modern vehicle bodies. To facilitate the future joining of FRP/steel structures with resistance spot welding, spot-weldable force-introduction elements may be embedded in the laminate as a joining interface. When welding the so-called inserts, thermal damage to the surrounding polymer should be avoided, as this is the only way to calculate the strength of the joint correctly. For this purpose, the paper presents a numerical model that allows the prediction of the temperature propagation during spot welding of FRP/steel joints with embedded inserts. The simulative approach is subsequently validated by comparison with experimentally determined temperature curves and in doing so, an excellent model prediction can be noted.

[ 8 ] Nieschlag, J.; Eisenhard, S. & Fleischer Jürgen, F. J. (2021), "Numerical design of rotationally molded composite tie rods ", Composite Structures, doi.org/10.1016/j.compstruct.2021.114687
Abstract
Rotational molding constitutes a promising manufacturing technology for rotationally symmetric components made of thermoset matrix with continuous fiber reinforcement. The present study deals with the numerical analysis of a rotationally molded composite tie rod with metallic load introduction elements. For this purpose, the adhesive joint between carbon fiber reinforced plastic and metallic load introduction element was investigated in more detail. Different geometries of a spew fillet were evaluated to reduce the stress peaks occurring at the ends of the overlap. A design of experiments was used to determine the influence of the different parameters. An optimized geometry was derived and compared with a reference in terms of stress distribution. Subsequently, test specimens were rotationally molded and mechanically tested. The results of the study show that the maximum stresses within the adhesive layer can be reduced with an optimized spew fillet, and thus a higher mechanical tensile load of the composite tie rod can be achieved.