Development of a simple mixed-mode fracture test and the resulting fracture energy envelope for an adhesive bond
Characterizing the fracture energy of bonded adhesive joints over a range of mode mixities often requires special fixtures or a variety of test configurations. By pairing a tapered and a constant thickness adherend, a hybrid double cantilever beam (DCB) specimen is proposed. This asymmetric tapered DCB configuration can be used to determine the fracture energy as a function of mode mixity. As the debond propagates, the relative stiffness of the adherends varies in a systematic manner, resulting in a range of mode mixities from 0° to approximately 20°. Strain energy release rates were obtained using corrected beam theory and a finite element fracture analysis. Single-leg bending tests were used to determine the fracture energy at mode mixity up to 56°. Constant thickness and tapered DCB tests were used to determine the mode I fracture energy. The resulting fracture envelope was constructed in order to show the dependence of the fracture energy on mode mixity for a two part acrylic adhesive.
KeywordsAdhesively bonded joints Mode mixity Fracture energy envelope Adhesive failure Asymmetric tapered double cantilever beam Two part acrylic
Unable to display preview. Download preview PDF.
- ASTM-D412-98a (1998) Standard test methods for vulcanized rubber and thermoplastic rubbers and thermoplastic elastomers-tension. Annual book of ASTM standards. West Conshohocken, ASTMGoogle Scholar
- ASTM-D3433-99 (2001) Standard test method for fracture strength in cleavage of adhesives in bonded metal joints. Annual book of ASTM standards. West Conshohocken, ASTM 15.06:225–231Google Scholar
- Chen B, Dillard DA (2002) Crack path selection in adhesively bonded joints. In: Dillard DA, Pocius AV (eds) Adhesion science and engineering-I: the mechanics of adhesion. Elsevier Science, AmsterdamGoogle Scholar
- Kanninen MF (1973) An augmented double cantilever beam model for studying crack propagation and arrest. Int J Fract 9: 83–92Google Scholar
- Pohlit DJ, Dillard DA et al Mixed mode dynamic fracture testing of bonded composite beams. J Adhes Adhes, in preparationGoogle Scholar
- Russel AJ, Street KN (1985) Moisture and temperature effects on the mixed mond delamination fracture of unidirectional graphite/epoxy. In: Johnson WS (eds) STP 876 delamination and debonding of materials. ASTM, Philadelphia, pp 349–370Google Scholar
- Singh HK, Chakraborty A et al Mixed mode fracture testing of adhesively-bonded wood using a novel dual actuator load frame. Wood Fiber Sci, in reviewGoogle Scholar