Design of Pressure Energy-Absorbing FRP Anchors and Numerical Analysis of Mechanical Properties

Conventional FRP anchor rods have low elongation and poor impact resistance, both of which do not meet the support requirements of rock burst roadways. Therefore, a pressure energy-absorbing FRP anchor rod composed of an FRP rod body, tray, energy-absorbing sleeve and round table nut was designed. Numerical simulations were carried out to study the mechanical properties of the FRP anchor rod in static tension and impact tension, and to compare its mechanical properties with those of conventional FRP anchor rods. The results show that the pressure energy-absorbing FRP anchor rod is stretched in four stages: the front-elastic stage, constant resistance to compression, the back-elastic stage and damage, with an additional constant resistance to compression stage compared with conventional FRP anchors. The elongation, energy absorption and impact resistance time of the pressure energy-absorbing FRP anchor rods are greater than those of conventional FRP anchor rods, and the mechanical properties of the pressure energy-absorbing FRP anchor rods are better than those of conventional FRP anchor rods. As the impact velocity increases, the energy absorption rate of the pressure energy-absorbing FRP anchor increases non-linearly. The impact energy and impact velocity have less influence on the breaking load, elongation and energy absorption of pressure energy-absorbing FRP anchor rods. The research results can provide a theoretical basis for the application and parameter design of the pressure energy-absorbing FRP anchor rod, and provide support for the safe and efficient mining of the mine.