Study on frictional behavior and maximum strength of GFRP members connected by high strength frictional bolts

In this research, in order to investigate frictional behavior, maximum strength and relaxation behavior of the frictional joints made of GFRP members connected by high strength bolts and splice plates, the slip test and the bolt relaxation test were conducted. The test specimens were prepared, which consisted of high strength bolts, connected plates made of GFRP and splice plates made of GFRP or stainless. The FE analysis was also executed to study mechanism of the stress concentration around the holes of the frictional joints and to estimate its maximum strength. The slip test showed that the slip coefficient of the specimens using the stainless splice plates was larger than 0.4. And it was found that the slip coefficient could estimate by tribology theory which was the science and technology of interacting surface in relative motion and of related subjects and particles. The bolt relaxation test for a year provided that the reduction of the bolt axial force of the specimen with the stainless splice plates was less than 5 % and lower than that of the specimen using the GFRP splice plates. From the FE analysis results, the maximum strength of the GFRP frictional bolted joint could calculate based on considering the stress concentration.