Recent work examining the nature of the failure process of glass/epoxy specimens in the single fiber fragmentation test showed that the matrix exhibited pronounced non-linear viscoelastic behavior during the test, and that the interfacial shear strength value obtained was dependent on the rate of testing. Furthermore, it was demonstrated that the load in the sample at the end of the test was much lower than the value predicted by assuming linear-elastic behavior, and that the first fragment break occurred when the actual load in the matrix deviated from the linear-elastic prediction. To study these issues further, the testing protocol was repeated using a polyisocyanurate resin to see if a similar non-linear viscoelastic response was observed. One result from this study was that the polyisocyanurate matrix did show non-linear viscoelastic behavior similar to the epoxy matrix. Interestingly, from preliminary results, the fiber fragmentation distribution of the glass/polyisocyanurate specimens was found to be independent of the strain rate used during the test, so that the calculated interfacial shear strength appears rate independent. This result contrasted with that of the glass/epoxy specimens where the fiber fragmentation distribution, and thus, the measured interfacial shear strength, was dependent on the rate of strain.
Proceedings Title: Proceedings of the 13th annual technical conference on composite materials
Conference Dates: September 21-23, 1998
Conference Location: Baltimore , MD
Conference Title: Technical Conference on Composite Materials
Pub Type: Conferences
adhesion, fragmentation, glass, interface, polyisocyanurate, polymer viscoelasticity