The Influence of Epoxy Matrix Properties on Delivered Fiber Strength in Filament Wound Composite Pressure Vessels

Filament winding is an efficient process for manufacturing composite pressure vessels that take advantage of the high structural efficiency of graphite fiber. One critical parameter in evaluating the performance of composite pressure vessels is burst strength. Burst failure in such vessels is primarily a result of fiber breakage. Once fibers start to break, the role of the matrix material becomes increasingly important. The major objective of this study was to investigate the influence of preselected epoxy matrix proper ties on delivered fiber strength and strength variability. It is shown that important matrix variables in determining delivered fiber strength and strength variability are the neat resin fracture toughness** ( G _Ic ); elongation at yield ( ε _ys ); initial modulus ( E _o ); and strength yield ( σ _ys ) .