A numerical determination of the fiber/matrix interlayer creep properties from the indentation creep testing in fiber reinforced composites

The present paper explores the possibilities of determining fiber/matrix interlayer creep properties from indentation creep testing on the fiber reinforced composites. Using creep finite element analysis the creep indentation test technique is analyzed in terms of indentation rates at constant loads. Emphasis is placed on the relationships between the steady creep behavior of indentation composite systems and the creep property/thickness of the interlayer. The role of indenter size effects is explicitly considered. It has also been confirmed that there is uniform shear stress in the interlayer, which can be calculated by a uniform distribution assumption. Two inverse FEM methods have been introduced to determine the creep property of the interlayer from the indentation experimental results. The results contribute to a better mechanical understanding of the interlayer creep properties and extending the application of indentation creep testing.