Single lap shear stress in hybrid CFRP/Steel composites

A critical parameter in a hybrid CFRP/steel composites is the shear stress between CFRP plies and steel foils.This paper presents an experimental and numerical research on the single lap shear stress in hybrid CFRP/Steel specimens in accordance with DIN EN ISO 1465. Four different types of specimens were tested: Vacuum basting surface treatment and pickling treatment. For each type of surface treatment two types of specimens were tested: Dry specimens and specimens immersed in water for 1000 h. The results show that vacuum blasting surface treatment is the one that withstands a higher shear stress and is simpler and less hazardous than pickling surface treatment. The results also show that this type of composite has low sensitivity to water absorption. A significant difference between the displacement measured by digital image correlation and the displacement measured by a LVDT was observed. Finite element models are able to predict the maximum shear stress of hybrid composites provided that the constitutive parameters of cohesive elements are validated by experimental results.