THE EFFECT OF ADHESIVE THICKNESS ON JOINT STRENGTH.
EXPLOSIVES RESEARCH AND DEVELOPMENT ESTABLISHMENT WALTHAM ABBEY (ENGLAND)
Pagination or Media Count:
Although Wakes hypothesis requires a linear relation between the strength of a joint and the adhesive thickness, it is statistically preferable to describe our experimental data by relating either log strength or linear strength to log thickness. The predicted slopes or thickness-dependences of the joint strengths are at least three orders greater than those observed. However, Wake assumes adhesive failure at the interface, which was not observed in any of our experiments. Cohesive failure might well favour the following argument. Both the preferred relations loglog and plainlog between joint strength and adhesive thickness have a possible theoretical basis, in the analysis by extreme value statistics of the negatively skewed frequency distribution of tensile strengths of rubbers, involving the frequency function of the maximum flaw. The former relation would hold if a Weibull type of distribution is used, and the latter if an exponential one. Thus it is possible that the dependence of joint strength on adhesive thickness is a consequence of the statistical basis of rupture. Author
- Adhesives, Seals and Binders