Design and development of aerogel-filled sandwich composite structures

• Main Author: Xu, Kaibin.
• Other Authors: Sunil Chandrakant Joshi
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Aeronautical engineering::Materials of construction; DRNTU::Engineering::Materials::Composite materials
• Online Access: http://hdl.handle.net/10356/42861
• Institution: Nanyang Technological University

Silica aerogel is an extremely lightweight material with an amazing heat insulation property. These properties present opportunities to develop lightweight and thermally insulating composite materials. The aerogel-filled sandwich composite structure can then be used in any applications that require shielding against undesired heat gain or unwanted heat loss. Possible applications of these composites include aircraft cabins, vehicle engines, thermal shelters, and building insulations. Acoustic insulation and moisture barrier properties can also be generated in such composites. Glass and carbon fibre reinforced aerogel-filled sandwich structures were designed, fabricated and tested during the course of this project. This report presents the work aimed at the development of a single step co-curing fabrication method for aerogel-filled sandwich structures. Thermal evaluation and impact response study of the fabricated samples are also presented. Woven fabric prepregs of carbon or glass were used in fabricating various grid forms wherein silica aerogel was filled to impart the necessary thermal insulating properties. The same prepregs were used for the facesheets over the aerogel-filled sandwich core. Fabricated specimens were then tested for studying the thermal performance. Experimental set-ups with the fabricated composite samples with a mounted heating element as the heat source were designed. Low velocity impact tests were also done on the fabricated samples to study the impact response and compare to a conventional honeycomb sandwich composite. Experimental results revealed that single step co-curing process allowed faster and less complex fabrication. Thermal evaluations of the fabricated samples demonstrated that the composites had good insulating properties. The sandwich composites were able to keep the cold side at a temperature that is warm to the touch (below 50°C) even when the hot side was maintained at 140°C. Impact studies showed that aerogel-filled sandwich composites were capable of withstanding impact loads along the walls of the aerogel compartments. The centre of the compartment did not receive impact load as well as the sides, and absorbed less energy. On the whole, aerogel-filled sandwich composites were comparable to conventional honeycomb sandwich composite in impact response.