The effects of rubber modification and adhesive thickness on the fatigue-fractured surfaces of epoxy adhesives under mode I cyclic loading were examined using fractals. When the energy release rate range, ΔGI is higher than 100 J/m2 the fractal dimension of fractured surfaces becomes high due to rubber modification under the same ΔGI. The fractal dimension decreases with increasing fatigue crack growth rate, da/dN. A relationship is given by the following equation between the parameter, S (= da/dN×ΔGI) and the fractal dimension, D for unmodified and rubber-modified adhesives. log S = log(da/dN·ΔGI) = α4·D+β4 where α4 and β4 are experimental constants. Whether the adhesives contain rubber particles or not, the fractal dimension as well as the da/dN-ΔGI relation is little affected by adhesive thickness.
|Number of pages
|Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A
|Published - 1997