Fracture and Mechanical Behavior of Nanoclay Reinforced Epoxy Adhesive in Bonded Joints

This study was intended to characterize the mechanical properties of nanoclay filled epoxy adhesive in single lap adhesively bonded joint under static (tension) loading. The nanoclay contents were 1, 3 and 5 wt% of epoxy resin. The nanoclay particles were distributed in the resin by stirring device and then the mixture of resin and clay particles was subjected to sonication using an ultrasonicator. In addition, double cantilever beam (DCB) fracture test was conducted to characterize the fracture performance of the reinforced adhesive joint. Also, the scanning electron microscope (SEM) photographs of the corresponding fracture surfaces were taken for morphological studies. The results showed that the adhesive joint with 1% nanoclay particles had maximum strength for tension loading and high DCB fracture toughness values are found in the case of neat epoxy adhesive bonded due to the plastic zone effect at the crack tip. As the content of nanoclay particles increased, the fracture toughness decreases, because the plastic zone is smaller.