This report investigates failure properties of a unidirectional fiber-reinforced E-glass epoxy resin matrix (CYCOM 5216). This material is used in military and commercial helicopter blades and structures and is commonly used in engine nacelles. Testing and failure analysis is critical for these structures, which undergo vibratory and complex aerodynamic loading. Defined manufacturing methods were modified to produce thick samples containing wrinkle defects. Wrinkles were added to simulate realistic marcelling, which commonly occurs within complex structures. All samples were validated using volume fraction experiments. Static uniaxial tension and five-point bending testing was performed as strain was measured using a multi-axis strain gage or an axial extensometer. Tensile and shear moduli, tensile strength, and shear strength were all determined. Shear modulus was determined through the use of a reinforced five point bending apparatus. The effects of fiber waviness on static strength were observed by testing samples with wrinkles of varying amplitude in both shear and tension. Fatigue analysis in this study differs from previous finite element crack growth studies due to the introduction of fiber waviness. For this reason, previous mixed mode bending tests and analytical methods were used with finite element techniques to improve failure prediction methods.

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