Expansion friction energy absorption anti impact cable and its mechanical characteristics

The failure of support materials caused by roadway rock burst has become a major engineering problem that needs to be solved urgently in mine roadway support. In considering that the ordinary cables are difficult to adapt to impact dynamic loads and the engineering problems such as structural deformation and fracture, based on the principle of plastic deformation of metal cylinder and frictional energy absorption, an expansion and friction energy absorption anti impact cable are designed. The theory of plastic mechanics is used to carry out the analytical analysis of the energy absorption principle of the energy absorption anti impact cable, and combined with the orthogonal simulation experiment, the influence law and sensitivity of the structural size and material properties of the energy absorption device on the energy absorption resistance are discussed. The main controlling factor that affects the energy absorption resistance of the energy absorption anti impact cable are obtained. The results show that during the energy absorption process of the energy absorption device of the energy absorption anti impact cable, the total energy absorption resistance of the energy absorption device can be divided into two parts: the expansion deformation resistance and the sliding friction resistance. There are significant differences in the influence of wall thickness, expansion ratio, yield to tensile strength ratio of the energy absorption tube, friction coefficient, and cone angle of the expansion cone on the expansion deformation resistance and sliding friction resistance of the energy absorption tube. The increase in the yield to tensile strength radio of the energy absorption tube will result in the total energy absorption resistance decreases, the larger the cone angle of the expansion cone, the faster the reduction speed. The sliding friction resistance is more sensitive to the changes in the expansion ratio of the energy absorption tube, while the expansion resistance is extremely sensitive to the changes in the cone angle of the expansion cone. Increasing the cone angle of the expansion cone can quickly reduce the sliding friction resistance and increase the deformation resistance of the expansion, thereby changing the proportion of the two in the total energy absorption resistance. Then the cone angle of the expansion cone is the same, the sensitivity of the sliding friction resistance to the expansion ratio of the energy absorption cube is significantly greater than the expansion deformation resistance. The friction coefficient directly affects the sliding friction resistance, but has no effect on the expansion deformation resistance. Six factors and five horizontal orthogonal simulation experiment results show that the primary and secondary order of factors affecting the total energy absorption resistance are energy absorption tube wall thickness, expansion cone angle, energy absorption tube yield ratio, extruded truncated cone height, energy absorption tube expansion ratio and friction coefficient. The relative error between the numerical simulation and theoretical calculation results of the total energy absorption resistance is less than 10%. The influence trend of the energy absorption tube wall thickness, expansion ratio, yield to tensile strength radio, friction coefficient and cone angle of the expansion cone on the total energy absorption resistance is basically consistent with the theoretical analysis. The results of theoretical analysis, numerical simulation and experiment have a high degree of agreement, which confirms the correctness of the analytical analysis model and numerical model of the energy absorption anti impact cable, which can be used as the theoretical basis for the design of the energy absorption anti impact cable structure. By adjusting the material and structural parameters of the energy absorption device, the energy absorption resistance can be adjusted between 300 kN and 500 kN to match different types of steel strands.