Digital image correlation and numerical analysis of CFRP-poplar timber interface subjected to modified single shear test

Abstract

This paper presents the results of a digital image correlation (DIC) and finite element (FEM) study of the interface between carbon-fiber-reinforced polymers (CFRP) and poplar timber. The interfacial behavior between CFRP and poplar timber is investigated. Specimens with different bond lengths were manufactured. The DIC was applied to capture the full strain field from two views of the specimens. The complementary use of DIC and FEM allowed us to obtain the strain field in the CFRP and lateral side of the poplar, capturing the detachment between the two materials. The results were compared in terms of shear strain, shear stress, slip distribution, and failure modes, derived experimentally and numerically. Once the FEM simulations were calibrated, a good agreement with the experimental results was found, proving the relevance of the presented FEM models in predicting the behavior of the interface between the two materials tested. The proposed test set-up revealed that the entire bond length is active from the onset until the debonding, regardless of the bond length. Although an identical failure mode was obtained for all bond lengths, the final strength of the interface was found to be dependent on the bond length.