Abstract
Behaviors of fatigue crack propagation (FCP) of the bulk epoxide resin cured with aliphatic a, ω-diamines H2N- (-CH2-) -m′NH2 (m′=2, 4, 6 or 12) have been studied as a function of the network structure. The concentration of network chains of the cured resins increased with decreasing m′ of curing agents. FCP rate (da / dn) of the cured resins decreased with decreasing the concentration of network chains at the same values of the stress intensity factor range ΔK.FCP bands (i. e. fatigue striations) were only indentified in the epoxide resin cured with DDMDA (m′=12), which has an decreased concentration of network chains.
It were concluded that the reduction of the concentration of network chains enhances FCP resistance of the cured epoxide resins and this enhancing of FCP resistance derives from the plastic deformation at the crack tip.
