Study of material damping in fiber reinforced composites modified with nanoparticles. Experimental investigation and numerical modelling : application to self-deployable structure

• Κύριος συγγραφέας: Καϊτσώτη, Βασιλική
• Άλλοι συγγραφείς: Kaitsoti, Vasiliki
• Γλώσσα: English
• Έκδοση: 2021
• Θέματα: Material damping; GFRPs; Free vibration analysis; Panel development mechanism design; Modelling; Απόσβεση υλικού; Ινώδη σύνθετα υλικά; Πείραμα ελεύθερης ταλάντωσης; Σχεδιασμός μηχανισμού έκπτυξης πάνελ; Μοντελοποίηση

In the present thesis, a fully developed research is conducted for the determination of material damping in glass fiber reinforced composites modified with various types of nanoparticles. The research consists of two main parts, the experimental determination of material damping and the confirmation of the experiment through modeling in the programme "Abaqus / CAE". First of all, material damping is determined experimentally in 5 materials which are: Unmodified GFRP, GFRP modified with 0.5% CNTs, GFRP modified with 1% CNTs, GFRP modified with 0.5% nSiC and GFRP modified with 1% nSiC. The construction and operation of the entire experimental set-up is described, as well as the components that the set-up is consist of, and the introduced errors and limitations of the experiment are reported. The results are analyzed and comparisons are made to obtain reliable results. The second part of this thesis concerns two analyzes that were performed to confirm the validity of the experiment. The specimens tested during the experiment are modeled in the "Abaqus / CAE" program in order to calculate the theoretical values of eigenfrequencies. The resulting data is entered in the "MATLAB" program and the theoretical calculation of material damping is conducted. The results showed that the deviation between theoretical and experimental values are negligible and are justified by the errors of the experiment. Thus, the experimental procedure is valid and reliable. Finally, the material with the largest value of material damping was applied to the panel development mechanism of a CubeSat. This analysis, performed in the “Solidworks” program, serves as an example of applying the material with the best energy dissipation capacity to a structure in which the oscillations must be suppressed quickly. In conclusion, the experiment proved to be reliable and accurate as the modeling through "Abaqus/CAE" confirmed its results. The application of the optimal material to a panel development mechanism is one of the many applications in which a construction must be made of a material with excellent damping capacity that can suppress oscillations and prevent a possible failure.