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.
Characterization of the electrical and magnetic material properties during high-frequency fatigue of WAAM-fabricated CrNi steels
Bachelor Thesis, Master Thesis, Diploma Thesis
Besides topology optimization, Additive Manufacturing allows for the targeted adjustment of material composition and, consequently, material properties. Knowing the relationship between these factors is therefore essential for producing such structures. As a basis for designing these graded structures, the magnetic, electrical, and mechanical properties of additively manufactured 316L and 17-4PH samples will be determined as a function of the build direction. Additionally, the local change in properties during cyclic loading is to be analyzed in interrupted tests. These findings will then serve as the basis for manufacturing graded structures.
Contact: Marc Alexander Hoffmann
Investigation of the fatigue behaviour of additively manufactured complex helix specimens made of AISI 316L
Master Thesis, Diploma Thesis, Bachelor Thesis, Research Project
The complex geometries of additively manufactured structures result in stress states with different proportions of tensile/compressive, bending and torsional stresses, which is why the relationship between the stress state and the component strength must be worked out for the design. Based on this background, uniaxially loaded specimens with complex geometry, which also resulted in considerable bending and torsional stresses, are to be analysed to what extent the stress state is related to the resulting strength. On this basis, a corresponding design approach will also be validated.
Contact: Paula Rahm
Investigation of the fatigue behaviour of additively manufactured complex eccentric AISI 316L specimens
Master Thesis, Diploma Thesis, Bachelor Thesis, Research Project
The complex geometries of additively manufactured structures result in stress states with superimposed tensile/compression, bending and torsion components. Consequently, knowledge of the influence of the stress state on the component strength is required for their design. Accordingly, this student thesis investigates the damage behaviour under different proportions of the aforementioned stresses. For this purpose, biaxial fatigue tests are carried out on eccentrically designed 316L specimens, whereby the extent to which process-induced defects affect the strength and damage mechanisms depending on the stress state is explicitly analysed
Contact: Paula Rahm
Design of a fixture and determination of welding parameters for ultrasonic welding of textiles
Research Project
Description: Ultrasonic welding is an efficient and fast joining process for creating textile joints. The aim of this project is to design a fixture for producing consistent textile weld seams.Suitable parameters for creating the weld seams are to be determined and compared using tensile tests. The comparison is made both between the parameter sets and between welds with and without the designed fixture. Knowledge in the field of construction is a prerequisite.
Target group: Engineering students from all disciplines
Start: Immediately or after consultation
Time frame: According to examination regulations
Contact: Fabian Thul
Construction of an anvil for ultrasonic roll seam welding of flat specimens
Research project
Description: Ultrasonic welding is an efficient and fast joining process for creating dissimilar material joints. The highly complex process is influenced by a large number of different parameters, including the clamping of the joining partners. The aim of this work is to design an anvil for the ultrasonic roll seam welding of flat specimens that enables consistent welding results. Knowledge in the field of construction is a prerequisite.
Target group: Engineering students of all disciplines
Start: Immediately or after consultation
Time frame: According to examination regulations
Contact: Fabian Thul
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
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