| Fiber reinforced composites, a combination of reinforcing fiber and resin matrix, offer many advantages over traditional materials, and have therefore found wide application in the aerospace and sporting goods industry. Among the advantages that composite materials offer, the most often cited are weight saving, high modulus, high strength-to-weight ratio, corrosion resistance, and fatigue resistance. As much as their attributes are desirable, composites are difficult to process due to their heterogeneous, anisotropic, and viscoelastic nature. It is therefore not surprising that the interrelationship between structure, property, and process is not fully understood. Consequently, the major purpose of this research work was to investigate this interrelationship, and ways to scale it to utilization. First, four prepreg materials, which performed differently in the manufacturing of composite parts, but were supposedly identical, were characterized. The property variations that were found among these prepregs in terms of tack and frictional resistance assessed the need for improved understanding of the prepregging process. Therefore, the influence of the processing parameters on final prepreg quality were investigated, and led to the definition of more adequate process descriptors. Additionally, one of the characterization techniques used in this work, temperature modulated differential scanning calorimetry, was examined in depth with the development of a mathematical model. This model, which enabled the exploration of the relationship between user parameters, sample thermophysical properties, and final results, was then compared to literature data. Collectively, this work explored and identified the key connectors between process, structure, and property as they relate to the manufacturing, design, and performance of composite materials. |
