Development of Toughened and Multifunctional Nanocomposites for Ship Structures.

摘要

This report consists of two parts. The objective of the first part of the research was to use a sol-gel in-situ produced silica nanoparticle- modified epoxy to manufacture fiber composites in order to enhance the mechanical properties of fiber composites. Vacuum assisted resin transfer molding (VARTM) process was used to fabricate unidirectional E-glass fiber reinforced silica/epoxy nanocomposites. Off-axis composite specimens with and without silica nanoparticles were tested to compare the compressive strength. A method for extracting the longitudinal compressive strength of the GFRP was developed based on the off-axis test data. Moreover, a microbuckling model was employed to predict the compressive strength based on the stress-strain curve of the silica nanocomposite. In the second part of the research, resonators are inserted into the core to provide a new degree of freedom in motion. Models for this new sandwich structure were first constructed. These models were subsequently employed to study wave propagation and the bandgap structure in the sandwich structure. Finally, sandwich specimens were manufactured and dynamic experiments were conducted to verify the analytical results.