Local Deformation and Fracture Mechanisms in Methacrylic Composites at the Fiber-Matrix Level: Insights from Nanoscale Digital Image Correlation

Unidirectional glass fiber-reinforced methacrylic composite specimens were subjected to transverse compression testing within a scanning electron microscope (SEM). Strain localization phenomena occurring at the fiber-matrix level were analyzed via nanoscale digital image correlation (nano-DIC). A finite number of 2- fiber arrangements were identified in the composite in terms of the orientation of the fiber pair with respect to the uniaxially-applied load. Two of these were characterized experimentally by nano-DIC. Consistent and repeatable deformation patterns were observed within both test configurations, giving confidence in the relevance of focusing on the orientation of fiber pairs with respect to the macroscopic loading direction for predicting the deformation (and failure) behavior of fiber-reinforced polymer composites at the constituent level.