GFRP锚杆拉伸实验应力集中数值分析

ensile strength is one of the important technical specifications of Glass Fiber Reinforced Plastic (GFRP) bolts, generally obtained by tensile experiments in laboratory. Experimental tensile strength of GFRP bolts varies with variation of grapping ways, failure forms and the middle piece length of the bolts. In practice, tensile behaviors and failure forms of GFRP bolts are different from that in laboratory experiments. Numerical computation of tensile stress of GFRP bolts are performed in this work. Numerical results indicate that stress concentration occur in GFRP bolts, the tensile stress of outer surface of the bolt is generally greater than that inside the bolt. A dimensionless variable , ratio of tensile stress and section-averaged tensile stress, is proposed in this paper. It is found that the maximum tensile stress appears in root segment of the bolt, away from which the stress concentration weakens. The stress concentration decreases with increase of the ration of middle piece length and diameter of bolt L/D, and the ratio approaches a stable value. The length of grapping segment of the bolt does not influence stress concentration behavior of the GFRP bolts. The numerical computation is consistent with tensile experiments of the GFRP bolts.