Bachelor thesis or Master thesis
Short-fiber-reinforced thermoplastics (SFT) are predominantly processed using the injection moulding process, as this method enables the economical, high-quality and automatic production of components. Due to the flow conditions within the melt, however, a layer structure with different fiber orientations is created across the wall thickness. These local anisotropies make it difficult to experimentally investigate material fatigue under oscillating loads, as the orientation of the fibers has a considerable influence on the damage mechanisms present. For this reason, an injection molding process was developed at IKV that makes it possible to produce test specimens with homogeneous, highly oriented fibers. With a thesis at IKV you have the opportunity to acquire in-depth knowledge and experimental skills and thus make an important contribution to research into material fatigue.
© Bild: Sato et. alThe work is related to this research project:
The fatigue mechanisms in short-fiber-reinforced plastics are not yet fully understood. For this reason, components fail prematurely, are replaced early or have to be over-dimensioned using large amounts of material in order to ensure operational stability. As part of the working group, you will contribute to research into material fatigue and thus support IKV in developing methods for safe dimensioning, taking sustainability into account.
Objective:
The aim of your work will be to carry out dynamic-cyclic tests on SFT and thus induce pre-damage. The resulting microscopic damage is visualized and examined using suitable methods. As part of the evaluation, you will systematically analyze the relationship between this damage and the residual strength and residual stiffness to be tested macroscopically. You will document your methodology and the knowledge you have gained in a Bachelor’s or Master’s thesis.
Your task:
| For a Bachelor's thesis, you will work on the following tasks | For a Master's thesis, you will work on the following tasks |
| Familiarization with dynamic-cyclic testing with a literature search on the state of the art | Familiarization with dynamic-cyclic testing with a literature search on the state of the art |
| Creating an experimental design | Creating an experimental design |
| Performing dynamic-cyclic tests for pre-damage of the material | Performing dynamic-cyclic tests for pre-damage of the material |
| Performing micro-computed tomography examinations to determine micro-damage | Performing micro-computed tomography examinations to determine micro-damage |
| Performance of quasi-static tensile tests to determine the residual stiffness and residual strength | Performance of quasi-static tensile tests to determine the residual stiffness and residual strength |
| Evaluation of the influences on the damage patterns that occur | Evaluation of the influences on the damage patterns that occur |
| Investigate and describe the relationship between the dynamic pre-damage and the residual strength or residual stiffness |