Comparison of Two Typical Adhesive Fracture Mechanics Considering Hygrothermal Aging

Carbon fiber reinforced polymer (CFRP) bonded structures are widely used for their lightweight and high specific strength. However, research on durability of adhesively bonded lap joints under hygrothermal conditions remain insufficient. Therefore, the aging process and residual strength of CFRP-bonded lap joints with different adhesives were studied. Condition of hygrothermal aging tests were set, then moisture absorption behavior of CFRP plate and adhesive layer were analyzed, respectively. Based on the same aging period, residual tensile strength of acrylic-based specimens and epoxy-based specimens were compared. To evaluate their performance and clarify the failure mechanisms, Finite element method (FEM) simulations were conducted. Load-displacement curve was recorded and morphology of the failure surfaces was analyzed by using a microscope.