Rate effects in mode-II fracture of plastically deforming, adhesively bonded structures

• Published in: International journal of fracture 2009-04, Vol.156 (2), p.111-128
• Main Authors: Sun, C., Thouless, M. D., Waas, A. M., Schroeder, J. A., Zavattieri, P. D.
• Format: Article
• Language: English
• Subjects: Adhesive bonding; Adhesive joints; Automotive Engineering; Bonded joints; Characterization and Evaluation of Materials; Chemistry and Materials Science; Civil Engineering; Classical Mechanics; Cohesion; Crack propagation; Deformation; Deformation effects; Ductile-brittle transition; Exact sciences and technology; Fracture mechanics; Fracture mechanics (crack, fatigue, damage...); Fracture toughness; Fundamental areas of phenomenology (including applications); Loading rate; Materials Science; Mathematical models; Mechanical Engineering; Original Paper; Parameters; Physics; Shear; Shear deformation; Solid mechanics; Static elasticity (thermoelasticity...); Structural and continuum mechanics
• ISSN: 0376-9429; 1573-2673
• DOI: 10.1007/s10704-009-9339-2

Results from a combined experimental and numerical investigation into the effects of rate on mode-II fracture of a plastically deforming, adhesively bonded joint are presented. It is shown that a cohesive-zone model has to be modified to include coupling between normal and shear modes of deformation when there is extensive shear deformation of the adhesive layer. A suitable cohesive-zone modeling strategy is described, and the mode-II cohesive parameters determined from the model are presented as a function of loading rate. Previous studies of the same system showed that the effects of rate in mode-I were limited to the probability that a crack growing in a toughened quasi-static mode would spontaneously make a transition to a brittle mode of fracture. No such transitions were found for mode-II fracture. Crack growth always occurred in a quasi-static fashion. While there was some evidence that rate might affect the mode-II fracture parameters, these effects were very limited even up to crack velocities of about 1,000 mm/s. Any possible effects was limited to a very minor increase in toughness and strength with increased loading rates. However, the magnitude of these possible increases were comparable to the magnitude of the uncertainties in the measured values.