Development and Expansion of Thermoplastic AFP Process Simulation(Masterarbeit)

Kurzfassung

Fiber Reinforced Plastics (FRPs) are high-performance materials that combine an excellent strength-to-weight ratio, stiffness-to-weight ratio, and exceptional corrosion resistance. In the aerospace sector, FRPs are used in critical structural components such as fuselages, wings, and support elements. A key advantage of FRPs is the ability to align the load-bearing fibers along the load paths, leading to significant improvements in structural efficiency compared to traditional metallic constructions in lightweight designs. Automated Fiber Placement (AFP) technology is used as an alternative to manual tape laying. The proper setup of such processes is crucial for optimal performance and configuration. This research focuses on the thermal simulation of the Thermoplastic Automated Fiber Placement (T-AFP) process, simulated in ANSYS, particularly the non-Autoclave methodology for in-situ consolidation of thermoplastic tapes to create a multi-layer composite structure. A transient thermal analysis is performed, simulating the actual placement of tapes, which are simultaneously positioned and heated by a laser heat source. In the first phase of the research, a method was developed to define the paths on the surface of a tool flat panel, based on its geometric characteristics, the orientation angle, the lay-up strategy, and the dimensions of the tapes. The approach aims at extracting the coordinates of the initial and final points of the trajectories. The 2D geometry of the tool is created in CATIA, with a tetrahedral mesh generated using the open-source GHSM software. A Python script is implemented to create CSV output files containing the coordinates of the extreme points of the paths, modeling the tapes as "boxes" on the tool surface. This method does not require complex geometric formulations, making it applicable to flat, square, rectangular, and arbitrarily shaped flat panels. The formulation is based on mathematical and trigonometric principles, such as the parametrization of the segment and vector calculations for defining the normals to the plane. A study on curved panels is also proposed. The second phase focuses on configuring the transient thermal analysis. Temporal steps are defined where the deposited tape elements are selected, and necessary thermal conditions are applied to simulate the process, including heating, cooldown, and optical control waiting times. To support the simulation, a Mechanical APDL script is written, as ANSYS does provide the necessary functionality for selecting the tapes during the analysis stages not in the GUI, only via script. Subsequently, the analysis is finalized by creating the 3D model of the laminate in contact with the tool, using ANSYS drawing tools and inserting all necessary geometric and thermal process parameters. The results obtained confirm the feasibility of the proposed method, providing consistent and comparable outcomes to the real process.