Original paper(Vol.48 No.7 pp.753)

Abstract:Effects of fretting on fatigue strength of mechanically fastened GFRP joint were examined experimentally under the tensile cyclic load. The laminated composite used in experiment was the glass fiber reinforced epoxy resin. The composite was bolted with two steel plates by SUS304 austenititic steel bolt as a lug joint. As the results, the following conclusions were obtained : 1) The higher fastening-up pressure of the bolt of the mechanical joint, moreover the lower stress amplitude, it was easy for fretting to develop, and also the fretting fatigue failure occurred from the crack which was initiated in the fretting region between specimen and washer. 2) In case of the mechanical joint failed at the circular hole, the lower contact pressure increased the deformation of the circular hole, and the fatigue strength of the mechanical joint, which failed due to the stress concentration, decreased with the lower contact pressure. 3) The fatigue strength of the mechanical joint tended to increase with the increase of bolt fastening-up pressure. 4) The fatigue strength of the mechanical joint tended to decrease in the higher cyclic frequency, and it was thought that the influence of temperature rise caused by the heat which GFRP material itself generated and by the friction which was caused by fretting.

Key Words:Fatigue, Fretting, GFRP, Mechanical joint