Dear students,
Some calls for proposals may still be in preparation. Initiative enquiries can be directed to the academic staff if you cannot find a suitable thesis here.
Simulation of a Sample Geometry in Abaqus for Electrical Steel Sheets under Ultrasonic Loading
Research Project
This study focuses on the simulation of a sample geometry in Abaqus for electrical steel sheets subjected to ultrasonic loading at 20 kHz. The samples should be designed to experience either bending or torsion stresses. To achieve this, an initial geometry should be modified to ensure that the material exhibits the desired displacement mode at the specified frequency. The work will involve iterative simulations to refine the sample design. While no extensive prior knowledge is required, experience with finite element method (FEM) environments is beneficial.
Contact: Elen Regitz
Investigation of the torsional fatigue behavior of additively manufactured AISI 316L
Bachelor thesis, research project or Master thesis
Powder bed based laser beam melting (PBF-LB/M) allows the production of topology-optimized components. The resulting complex geometries give rise to gradient stress states with considerable proportions of torsional stresses. In order to investigate the extent to which such cyclic torsional stresses affect the damage behavior, torsional fatigue tests are to be carried out on samples made of AISI 316L produced using PBF-LB/M. Based on the results obtained, the fatigue behavior is to be analyzed and compared with the behavior resulting from other stresses. In particular, the influences of process-induced defects and the rough “as-built” surface are to be evaluated.
Contact: Paula Rahm
Interfaces in composite materials and multi-material joints
Masterthesis
Many properties of composite materials and material composites are determined by the interfaces between the individual materials. The aim of this thesis is to analyse the interfaces of ultrasonically welded composite materials in detail and correlate them with process parameters.
Contact: Moritz Liesegang
Investigation of the fatigue behaviour of duplex steel as a function of the manufacturing process
Masterthesis
The fatigue behaviour of a duplex steel (1.4462) in the high-cycle fatigue range is to be investigated as part of this work. Duplex steel consists of equal proportions of austenitic and ferritic phases, with a good combination of mechanical properties and corrosion resistance. The samples are available in a conventionally cast state and in two additively manufactured states. The aim is to investigate the fatigue behaviour in load increase and single-stage tests and to carry out comprehensive characterisation depending on the manufacturing process using microstructural analyses.
Contact: Constanze Backes
Frequency dependence of plastic deformability during ultrasonic welding of metals
Masterthesis
Ultrasonic welding is an innovative and promising joining technique for hybrid material systems. The joining of dissimilar material types is interesting for high-performance structures, e.g. in electronics or aviation. The plastic deformability of metallic joining partners during the process is a basic prerequisite for a successful process and the production of robust welded joints. This work therefore aims to investigate the plastic deformation of metal-safe materials during the ultrasonic welding process as a function of the working frequency.
Contact: Moritz Liesegang
Design of ultrasonic welding sonotrodes
Bachelor thesis or research project for Master students
Sonotrodes are tools that transmit the vibration into the components during ultrasonic-assisted processes such as ultrasonic welding. To do this, the sonotrode must be acoustically designed so that the natural frequencies match those of the rest of the system. The design is comparatively complex, depending on the geometry of the sonotrode and the material used, and is typically carried out using finite element simulation.
In this work, ultrasonic welding sonotrodes are to be designed using CAD and FEM, which differ in terms of geometry and the materials used.
Contact: Moritz Liesegang
Ultrasonic welding of metal/glass-joints - Interface formation
Bachelor thesis or research project for Master students
Ultrasonic welding is a fast method of joining multiple materials. Brittle materials such as glass are challenging but desirable joining partners. In particular, the understanding of glass as a joining partner is interesting due to its state as an overcooled melt rather than a solid material. In this work, experiments will be carried out on the joining of metal and glass, which has been the focus of research at the WKK decades ago, with a focus on interface formation.
Contact: Moritz Liesegang