An Analytical Study on Mechanical Behavior of Crack Propagation in CFRP Mode 2 Adhesive Specimens through Simulation Analysis

Background/Objectives: CFRP has been utilized as composite material at various industrial fields. This paper investigates the fracture behavior at the part joined with adhesive of the structure for Mode 2. Methods/Statistical Analysis: The bonded structure for Mode 2 composed according to thickness is applied under the tensile load. As the fracture behavior is investigated by the finite element method, the previous data are secured before experiment. The contact condition is maintained on the area touched with each other until the maximum tensile bonding strength. So, the bonding condition on this model is cleared when the occurred stress becomes beyond this stress. Findings: As the thickness is increased, the reaction force and the displacement are increased until falling off at the bonded interface. By the separation at the adhesive interface of the joined part with an increase in thicknesses of the two joined specimens, an increase in structural stability for the joined structure could be seen. The various stress distribution and the transferred direction of load at bonded interface can be investigated. As the thickness of a specimen applied to the joined CFRP was increased, equivalent stresses due to displacement could be seen to be gradually increased. At this time, the stresses produced at the adhesive interface could be seen to affect the specimens and the equivalent stresses could also be seen to be increased. However, since the fracture of specimen could be seen not to occur at a lower value than the tensile strength of the applied specimen, the stability of the structures could be seen as being guaranteed. Application/Improvements: On the basis of this study result, the safety of bonded structure can be evaluated and the safe design data can be obtained by applying this result.