The mechanical properties of thin-walled plastic components are limited. One approach of improving the strength is to apply individual adapted Fused-Deposition-Modelling-structures onto the thin-walled components. To achieve an optimal reinforcing effect, the properties of the FDM-structure must be optimized first. This project will focus on the variation of the FDM process parameters, because they have the most significant impact on the mechanical properties. The results of the parameter variation shall provide findings to develop design and process guidelines for FDM-structures that are used for the partial reinforcement of hybrid structures. Besides the mechanical properties, the lightweight potential of the FDM-structure must be considered, too.
This project aims to determine design and process guidelines for FDM-reinforcement-structures, which are aligned for specific load cases and shall be used for a partial reinforcement of lightweight parts. The reinforcement structure shall provide maximum increase of strength and stiffness with minimum increase of weight. To realize the maximum increase of the mechanical properties the inner structure is adjusted to the specific load case by using different parameters for the layer generation. In addition to this, the design of the FDM-part will be varied to achieve a weight increase as minimal as possible. The used material for the FDM-reinforcement-structure is Ultem 9085.
The strength and stiffness for various inner part structures will be determined for the different load cases by using mechanical tests (tensile, compression, flexural, impact and torsional strength). As a result, a list of load specific designs and process guidelines for the FDM-structure will be compiled. Additionally a modeling of the mechanical strength of FDM-parts will be developed. The strength is modeled as a function of the inner part structure which is directly depending on the process parameters. The modeling shall support the strength analysis of the different load cases.
At last, the design and process guidelines will be verified on a real lightweight part. This part will consist of two components, a GITBlow-part and the FDM-reinforcement-structure (Figure 1). To realize a joint between both parts, the FDM-structure is inserted to the injection mold first. Then the GITBlow-preform is inflated and adheres to the FDM-structure. The gain structure is only added to the thin-walled area of the GITBlow-part. For that hybrid component, different mechanical tests will be carried out.