Fracture propagation analysis on two component type acrylic adhesive joints

Detailed investigation on fracture toughness and destruction process was made on acrylic adhesive joints. Tapered double cantilever beam (TDCB), end notched flexure (ENF), and lap shear test were measured using acoustic emission (AE) and digital image correlation (DIC). Two types of secondary generation acrylic adhesives (SGA) were compared. Under lap shear and TDCB measurements, cumulative AE energy reflects the difference between elastomer and acrylic composition in existence form observed under transmission electron microscope (TEM) images. The mode 2 energy release rate G(2c), was a smaller value than the mode 1 energy release rate G(1c), when derived using linear fracture mechanics. Nonlinear effect is necessary to determine an accurate G(2c) value. The AE source location analysis, performed in an ENF test, detected the relationship between an actual crack length and an AE generation position. The result of this research is useful to understand the fracture process in a SGA bonded joint.