A TECHNIQUE FOR MICROANALYSIS OF MATRIX AND FIBER-MATRIX INTERACTION DURING COMPOSITE DEFORMATION

Composite materials deform inhomogeneously, necessitating an experimental technique capable of determining strain on a local basis. This paper describes the stereoimaging technique and its application in studying composite materials, particularly in analyzing the deformation around fatigue crack tips in graphite reinforced epoxy and boron fiber titanium alloy matrices. The objective is to utilize stereoimaging to achieve high spatial resolution measurements of displacement, strain, and stress at the composite's surface, enabling insights into the mechanical response of matrix and interfacial regions under loading conditions. Methodologically, the stereoimaging technique compares two photographs of the composite taken before and after load application, allowing for the visualization of displacements through a stereoviewer. Results demonstrate that the technique can derive strains within a few micrometers and has been successfully used to characterize deformation in various composite materials, highlighting its effectiveness in studying the intricate interactions within composite structures. This study underlines the significant contribution of stereoimaging to advancing the understanding of composite material mechanics.