Why LEFM is not Applicable for Bonded Joints

摘要

Adhesive bonding technique is very attractive to joining composite structures. In general, a bonded joint features an adhesive layer sandwiched by two relatively rigid structural components. Various methods have been used to predict the joint strength without much success. Recently, researchers have attempted to use linear elastic fracture mechanics (LEFM) for the prediction of joint strength. However, there are more questions raised than answered. In this presentation, the inadequacy of LEFM in characterizing the fracture behavior in bonded joints is discussed. An alternative method using crack tip opening angle is proposed and validated experimentally.