Author, Institution: Tomas Kuncius, Kaunas University of Technology
Science area, field of science: Technological Sciences, Mechanical Engineering, T009
Scientific Supervisor: Assoc. Prof. Dr. Marius Rimašauskas (Kaunas University of Technology, Technological Sciences, Mechanical Engineering, T009)
Dissertation Defence Board of Mechanical Engineering Science Field:
Chief Researcher, Dr. Rolanas Daukševičius (Kaunas University of Technology, Technology Sciences, Mechanical Engineering, T009) – chairperson
Assoc. Prof. Dr. Regita Bendikienė (Kaunas University of Technology, Technology Sciences, Mechanical Engineering, T009)
Prof. Dr. Mangirdas Malinauskas (Vilnius University, Nature Sciences, Physics, N 002)
Prof. Dr. Wiesław Ostachowicz (The Szewalski Institute of Fluid-Flow Machinery, Poland, Technology Sciences, Mechanical Engineering, T009)
The doctoral dissertation is available on the internet at the library of Kaunas University of Technology (K. Donelaičio g. 20, Kaunas).
This work examines the applicability of the Fused Deposition Modeling (FDM) technology for printing composite structures by reinforcing thermoplastic matrix structures with continuous carbon fiber (CCF). The main aim of the scientific research is to develop and validate an FDM technology for the rapid fabrication of complex geometry CCF reinforced composite structures. To achieve this aim, an innovative method for impregnation of CCF before the printing process was developed and tested. A new printing module has also been designed and manufactured, capable of printing composite structures reinforced with CCF. Developed printing module and the printing process based on Fused Deposition Modeling has been experimentally tested. Tensile, flexural and shear tests were carried out in order to determine the main mechanical characteristics of the printed material. Adhesion between individual layers, and between the matrix and the reinforcing material, was also determined. Two different methods, computed tomography and dissolution of the matrix material were used in order to determine, the volume of air void and the percentage of carbon fiber in the printed structures In order to reduce the volume of air cavities and improve mechanical properties, secondary impregnation of printed composite structures in epoxy resin has been developed and tested. The manufacturing methodologies and equipment developed during this research can be used for the production of complex structural design continuous carbon fiber reinforced composite functional parts . The results of technological development, such as various impregnation techniques, printing modules and the identification of the most suitable FDM process conditions as well as parameters can be used for rapid fabrication of customized lightweight functional components employed in the automotive and aviation industries or medical sectors and any other newly emerging scope of applications including autonomous robotics, human assistive devices, vehicle or aircraft parts where the mass-to-stiffness ratio is of top importance. The mechanical properties and print quality characterizations of printed composite structures provide valuable information and knowledge for the further technological development of the process.