Research
Composites Department

Main research topics in the Composites Department

© FBG / C. Bierwagen
© FBG / C. Bierwagen
© FBG / C. Bierwagen

The scientific activities in the Department Composites can be divided into the following two main research areas:

Material modeling and nanocomposites

A first theme  in this team concerns  the development of material laws and failure models for composites and their application  in the analysis of material  and joint failure of composite structures and layered structures.  A second  theme is the computer aided material development using atomistic simulation methods. Different scales and multiscale analysis are relevant aspects  in this team.

Stability, dynamics and fatigue

This team is concerned with the stability analysis and dynamic analysis  of slender  and thin-walled structures.  A second theme is the fatigue analysis  of composite structures. Important aspects in this team are probabilistic analysis and reduced order modeling.  

RECENT RESEARCH PROJECTS

Material Modeling

  • Virtual Materials and their Validation: German-French School of Computational Engineering (ViVaCE)
    Compressive failure mechanism of unidirectional fibre composites has been studied extensively over the past decades. Stochastic fibre misalignments were identified as an essential factor in the prediction of compressive strength. There is a need to characterize the effects of distribution of misalignment on the strength values in compressive regime. Hence, the scope of this project is to further the development in this regard and extend the definition of failure surfaces under compressively dominated loads by statistical information. A probabilistic definition of failure surface based on imperfections at micro level, and a subsequent experimental validation are the goals of the project. This would lead to subsequent better representation of material properties at the macro scale.
    Leaders: Prof. Dr-Ing. habil. Raimund Rolfes
    Team: Nabeel Safdar, M.Sc., Benedikt Daum, Dipl.-Ing. Dr.
    Year: 2016
    Sponsors: Deutsche Forschungsgemeinschaft – DFG (International Research and Training Group IRTG1627)
    Lifespan: 01.12.2016 – 30.09.2019
  • Development and validation of a virtual process chain for composite structural components considering imperfections with application to a rotor blade component (Prosim R)
    Within the scope of this research project, the essential parts of the process chain in the production of a rotor blade are to be numerically simulated and fundamentally investigated. The primary goal is the reduction of defects in the production of fiber composite materials with the help of simulating the full process chain (manufacturing simulation and structural analysis). In order to obtain a statement on material behaviour and progressive failure, the ISD will extend the sequential multi-scale analysis by including imperfections at the ISD. The results of the draping and infusion simulation are thereby the input information.
    Leaders: Prof. Dr-Ing. habil. Raimund Rolfes
    Team: Gerrit Gottlieb, M.Sc., Benedikt Daum, Dipl.-Ing. Dr.
    Year: 2017
    Sponsors: German Research Foundation (DFG) - Project number 329147126
    Lifespan: 01.08.2017 – 31.07.2020

Structures

  • CraCpit - Development of a safety cockpit for gliders
    The aim is to develop a crash retrofit solution made of composite materials for gliders. Particularly challenging is the rapid loading, which requires a non-linear viscoelastic damage model. The high complexity of the model, resulting from the high level of geometric detail. The energy dissipation and the separation of subcomponents is a particular challenge during the explicit calculation. The developed and simulated retrofit solution is validated in a large-scale test on a glider.
    Leaders: Prof. Dr-Ing habil. Raimund Rolfes
    Team: Oliver Dorn, M.Sc.
    Year: 2018
    Sponsors: Luftfahrtforschungsprogramm V-3 - Bundesministerium für Wirtschaft und Energie (BMWI)
    Lifespan: 2018-2021
  • Improved structural performance through the use of random field analysis.
    The research performed within this project uses the effect of random variations in structure’s geometry and/or material to get information on local sensitivity of structures to deviations from their baseline value. This information cannot only be useful in quality assurance, by finding areas most sensitive to deviations, but can also be used to improve the design. This approach can load to an increase in structural parameters such as buckling load, fatigue life and others.
    Leaders: Prof. Dr-Ing habil. Raimund Rolfes
    Team: Sander van den Broek, M.Sc.
    Year: 2019
    Sponsors: SE²A excellence, Cluster of DFG
    Lifespan: 2019-2022
  • Multistable Morphing Structures using Variable Stiffness Composites
    The research project aims at developing multistable structures with morphing capabilities. A variable stiffness composite is used which allows stiffness tailoring with much larger design space. The developed semi analytical method is validated well within a Finite element framework. In this work, the concept of static, smart and dynamic actuations are exploited on bistable laminates to reduce the snap-through requirements.
    Leaders: Prof. Dr-Ing habil. Raimund Rolfes
    Team: Anilkumar P M Nair, M.Tech.
    Year: 2019
    Sponsors: Deutscher Akademischer Austauschdienst (DAAD)
    Lifespan: 2019-2021

Nanocomposites

  • Acting Principles of Nano-Scaled Matrix Additives for Composite Structures (FOR 2021)
    The research project aims at gaining a comprehensive understanding of the acting mechanism of nano-scaled additives to polymer matrices of continuous fibre reinforced polymer composites with respect to improved matrix dominated properties. Particularly, a sequential multi-scale simulation scheme for the prediction of mechanical properties is developed, ranging from particle-matrix interactions on nano scale up to fibre reinforced materials on micro/meso scale. It combines Finite Element and atomistic simulations based on the Molecular Dynamic Finite Element Method (MDFEM).
    Leaders: Prof. Dr-Ing. habil. Raimund Rolfes
    Team: Atiyeh Mousavi, M.Sc., Johannes Fankhänel, Dipl.-Ing.
    Year: 2017
    Sponsors: Deutsche Forschungsgemeinschaft (DFG)
    Lifespan: 01.07.2017 – 31.10.2020
  • Challenges of industrial application of nanomodified and hybrid material systems in lightweight rotor blade design (HANNAH)
    The HANNAH research project is the follow-up to the LENAH research project. In LENAH, material systems from the fields of nanomodified materials and hybrid laminates were developed, tested and numerically simulated. This allowed the high potential of these material systems for the application in rotor blade design to be demonstrated under laboratory conditions. The investigated material systems are far superior to currently established materials, especially with regard to fatigue resistance. In the follow-up project HANNAH the (further) development of production and simulation methods for these material systems for industrial standards is now in the foreground. On the one hand, the aim is to guarantee the excellent properties of the developed material systems in large-scale production and to be able to simulate the mechanical behaviour to answer industry-related issues. In this context, the ISD develops material-specific simulation models in order increase time and cost efficiency for processes of material development and component design for nanomodified materials and hybrid laminates.
    Leaders: Prof. Dr-Ing. habil. Raimund Rolfes
    Team: Christian Gerendt, M.Sc. ; Betim Bahtiri, M.Sc. (ab 1. Mai 2020)
    Year: 2019
    Sponsors: Federal Ministry for Economic Affairs and Energy (BMWI) - FKZ 0324345A
    Lifespan: 01.03.2019 – 28.02.2022

Fatigue

  • Challenges of industrial application of nanomodified and hybrid material systems in lightweight rotor blade design (HANNAH)
    The HANNAH research project is the follow-up to the LENAH research project. In LENAH, material systems from the fields of nanomodified materials and hybrid laminates were developed, tested and numerically simulated. This allowed the high potential of these material systems for the application in rotor blade design to be demonstrated under laboratory conditions. The investigated material systems are far superior to currently established materials, especially with regard to fatigue resistance. In the follow-up project HANNAH the (further) development of production and simulation methods for these material systems for industrial standards is now in the foreground. On the one hand, the aim is to guarantee the excellent properties of the developed material systems in large-scale production and to be able to simulate the mechanical behaviour to answer industry-related issues. In this context, the ISD develops material-specific simulation models in order increase time and cost efficiency for processes of material development and component design for nanomodified materials and hybrid laminates.
    Leaders: Prof. Dr-Ing. habil. Raimund Rolfes
    Team: Christian Gerendt, M.Sc. ; Betim Bahtiri, M.Sc. (ab 1. Mai 2020)
    Year: 2019
    Sponsors: Federal Ministry for Economic Affairs and Energy (BMWI) - FKZ 0324345A
    Lifespan: 01.03.2019 – 28.02.2022
  • Global-local thermomechanical analysis of fracture in polycrystalline silicon shells using a phase-field approach.
    Abstract: The existing works in the literature addressing damage events in PV-Modules have different drawbacks and needs for improvements. On the one hand, the lack of a computationally efficient multiscale-based framework to model progressive failure in PSWs is observed. Furthermore, a coupled thermomechanical phase-field modeling framework for shells based on the geometrically nonlinear theory which takes into account the anisotropy effects as well as the presence of residual stresses is not yet available. Thus, the present proposal aims at covering these shortcomings in a unified way and at modeling progressive failure at both the micro- and macroscale by developing a theoretically robust and computationally efficient framework. This project is carried out in a close collaboration with the Institute of Applied Mechanics of the Technische Universität Braunschweig.
    Leaders: Prof. Dr-Ing. habil. Raimund Rolfes
    Team: Muzzamil Tariq, M.Sc.
    Year: 2020
    Sponsors: DFG, German Research Foundation
    Lifespan: Muzzamil Tariq, M.Sc.