Effect of Tool-Part Interaction in Composite Manufacturing Simulations
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Applied mechanics (MPAME), MSc
Publicerad
2024
Författare
Tzanetou, Afroditi
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Carbon Fiber Reinforced Polymers (CFRP) are widely used across multiple industries, especially in aerospace due to their lightweight and superior specific stiffness and strength. Despite their advantages, their mechanical properties are significantly influenced by the manufacturing process, since factors as the curing process and tool-part interactions are critical in the development of defects like shape distortions. Examining the critical parameters of CFRP manufacturing process with a focus on of tool-part interaction, the main goal of this master thesis is the development of validated methods for Finite Element (FE) models to investigate the process-induced distortions and predict the tool effect on the processing. In the frame of this project, L-shaped CFRP components are manufactured and FE models are built-up in LS-DYNA simulating the curing and demolding process of the composites so as to predict the resulting shape distortions in terms of spring-in and warpage. The FE simulations are validated using measurements from the manufactured components, and the numerical results are analysed aiming to assess the impact of tool-part interaction on process-induced distortions. The goal is to determine whether this interaction significantly influences the distortions, justifying its consideration in future studies. The results of this master thesis indicate the importance of selecting a high-fidelity material model in numerical simulations, since linear material models poorly predict spring-in and warpage when compared to experimental results. Using a simplified composite constituent model, the FE simulation is inadequate for capturing the tool effect and the tool-part contact simulation becomes ineffective. Implementation of more efficient methods to numerically measure spring-in and warpage are recommended to enhance the FE validation process. Additionally, experimental results suggest that titanium tools induce more significant deviations from the flat composite surface than steel tools, while asymmetric laminates exhibit considerably higher warpage than quasi-isotropic and unidirectional ones. Based on these findings, a re-evaluation of the assumptions made in this study is also suggested, so as the FE simulations developed in this work can be recognised as a precise tool for accurate spring-in and warpage prediction.
Beskrivning
Ämne/nyckelord
CFRP , L-shaped composites , Finite element model validation , tool-part interaction , curing process , spring-in , warpage