Student Theses

In the European research project EXAELIA, the University of Stuttgart is responsible for designing a scaled, modular flying testbed that can be used to investigate the integration of various propulsion system architectures. At the current stage, the main focus is on foundational concept studies and the preliminary sizing of key components.

In the attached file, you will find the thesis topics that are currently available.

Auxetic structures are characterized by a negative transverse contraction coefficient and exhibit exceptional mechanical properties such as increased energy absorption and dissipation, improved damage resistance, and adaptable stiffness behavior. While auxetic lattice structures have been studied predominantly in isotropic materials, their combination with anisotropic fiber composites has not yet been sufficiently researched.
The aim of this work is to design, manufacture, and experimentally investigate an auxetic lattice structure made of a fiber composite material. These lattice structures are to be placed in the context of engine suspension for rear-mounted engines in novel aircraft designs. The focus is on analyzing the mechanical behavior under quasi-static loading and the vibration characteristics of the structure in order to evaluate the potential of auxetic FRP lattices for lightweight design.

The study shall be performed computer-based with a virtual, verified ATD (Anthropomorphic Test Device)
representing an average pilot with and without helmet, a typical helicopter seat and harness system, including
an airbag, focusing on a neck-collar for the air bag.
Your main responsibilities will include:
• Literature Review: Researching current state-of-the-art airbag systems and biomechanical injury criteria.
• Familiarization with models & tools (CATIA, FE solver LS-DYNA, pre/post processing, scripts)
• Model Development:
o Building a simplified FE model of the neck-collar airbag (initially modelled as fully inflated).
o Developing a simplified model to account for helmet effects (as additional mass or simplified FE mesh).
o Simulation Setup: Integrating the ATD, seat, harness, and new airbag/helmet models within the LSDYNA
environment.
• Parametric Study:
o Performing simulations based on certification-relevant crash pulses spanning over typical helicopter
accident scenarios, covering dominant vertical or longitudinal accelerations with lateral components.
o with and without airbag,
o with and without helmet
• Analysis & Assessment: Evaluating the impact of parameters on survivability using injury criteria (HIC,
neck loads, etc.) and head trajectory analysis.
• Documentation: Providing full technical, CAD, and FE model documentation.

The aim of this work is to investigate the applicability of the SimTex FE solver, a solver optimized for contact-intensive, multi-fiber-based simulation models, to the numerical simulation of the coreless filament winding manufacturing process, as well as a downstream expansion-based modeling strategy to consider fiber bundle deformation. Within the scope of the thesis, a Python-based optimization workflow with pre- and post-processors for modeling and evaluation will be expanded and used as the basis for parameter studies and parameter calibration using small reference structures. The results will then be analyzed with regard to the limitations of the modeling approach, the computation time, and deviations from geometric measurement data of corresponding measurement of test specimens.

Work Packages:
- Literature review and induction (Coreless filament winding (CFW), textile submesoscopic multifilament modeling strategies)
- Investigation of the suitability of the SimTex solver for the problem
- Advancement of a pre- and postprocessor for modeling and calibration
- Investigation of parameters affecting the modeling results and calibration
- Validation of the geometrical results against existing experimental data
- Documentation and presentation of the results

In the European research project EXAELIA, the University of Stuttgart is responsible for designing a scaled, modular flying testbed that can be used to investigate the integration of various propulsion system architectures. At the current stage, the main focus is on foundational concept studies and the preliminary sizing of key components.

In the attached file, you will find the thesis topics that are currently available.