EXPERIMENTAL STUDY ON FATIGUE BEHAVIOR OF ONE DIRECTION FRP SHEETS

摘要

The purpose of this study is to examine the tensile fatigue behavior of Carbon, Glass, and PBO (Poly-p-phenylene-benzobisoxazole) Fiber Reinforced Polymer (CFRP, GFRP, and PFRP) sheets as three types of well used composites for structural retrofitting and strengthening of civil engineering structures. First, a test program with a series of specimens is summarized in the paper. Based on the experimental results, strain of all kinds of FRP sheets is increased by the influence of fatigue loading. Then, GFRP strain is bigger than that of other FRP. The matrix crack, which initiates by fatigue loading, distribution is different each of them. Moreover, the fatigue behavior is finally characterized by the conducted S-N diagram representing the relationship between maximum or amplitude load (S) and the number of cycles (N) at tensile rupture on a logarithmic scale. These curves of all kinds of FRP sheets are almost same and the shape seems to be a sideward crawl. And it the limit maximum stress is about 60 percent of tensile strength.