Incipient heat damage in carbon fibre reinforced composites

This study highlighted a recent trend of increasing usage of Polymer Matrix Composite (PMC) materials in aircraft structures in the Aviation industry. Commercial aircraft Original Equipment Manufacturers (OEM) such as Airbus and Boeing are leveraging on the advantages composite materials possess to increase fuel efficiency and hence reduce operating and maintenance costs. PMC also provides excellent corrosion and fatigue resistance which will reduce aircraft down time in the form of maintenance and Aircraft on Ground (AOG). However, usage of the PMC materials are limited by its service ceiling temperature and is dictated by the resin constituent. Elevated temperatures resulting from localized heating during lightning strikes or near engine exhaust gas wash can caused incipient heat damages in PMC structures. Incipient heat damaged PMC has adverse effects on the properties of material. This study seeks to investigate and analyze how incipient heat damage in PMC affects its mechanical and thermal properties. Specimens are fabricated and cured using autoclave. Incipient heat damage is introduced to specimens at near degradation temperature (Td), and at two other test temperatures below and above glass transition temperature(Tg). The values of Td and Tg are determined by analyzing the results of the Thermogravimetry Analysis (TGA) and Differential Scanning Calorimetry (DSC). Next, the mechanical properties of the specimens are determined using three point bending tests as per ASTM D790 standard and Dynamic Mechanical Analysis (DMA). The results are evaluated and analyzed to show the effect of incipient heat damage on mechanical properties.Bachelor of Engineering (Aerospace Engineering