Study On The Extrusion-friction Energy-absorbing Anchor

Anchor support is a kind of "active" support and a main support form of mines around the world. According to the traditional supporting anchor of coal mine does not have the function of giving way and energy absorption, the method of numerical simulation and experimental research combination is used to study the mechanical properties of extrusion-friction anchor.The extrusion-friction anchor is a mechanical device consisting of sleeve, dishing anchor tray, hexagonal lining tube and the none longitudinal rib rebar resin anchor. According to this structural form of extrusion-friction anchor, the feasibility of structure scheme is studied. The numerical simulation software ANSYS/LS-DYNA is used to set up the finite element model of extrusion-friction anchor. The controlling variable method is used to study the influence of component sizes on energy absorption effects. The results showed that:the wall thickness of hexagonal lining tube, end diameter, height of friction column station and height of extrusion truncated cone are all have positive correlation with resistance value.The mechanical properties of dishing tray are studied based on the numerical simulation software ANSYS/LS-DYNA. The study found that:the dishing anchor tray made by 45# steel has a certain advantage to confront impact load. So it can be used to support the use of extrusion-friction anchor. The whole finite element model of extrusion-friction anchor is set up to study the mechanical properties of extrusion-friction anchor under impact loading. And the impact loading is realized by using a mass block to struck the anchor in a certain speed. The results showed that:the extrusion-friction anchor has an obvious advantage to confront impact load, and has the ability to withstand repeated impact.The laboratory tensile test of extrusion-friction energy absorption anchor is conducted by using WAW-600C microcomputer control electro-hydraulic servo universal machine.The test study the influence of end diameter of anchor rod body on energy absorption effects of extrusion-friction energy absorption anchor. The results showed that:the end diameter ranges from 28mm to 29mm has an obvious effects on resistance value. The test result is consistent with numerical simulation results. So a higher strength end material should be chosen to maintain a relatively stable resistance curve.The development of extrusion-friction energy absorption anchor overcomes the insufficient of the ductility of traditional rebar anchor depending entirely on material plastic deformation, and realizes the high strength and extensible performance of anchors.