Structural Optimization and Energy Absorption Characteristics of Double-Layer Variable-Diameter Energy-Absorbing Components for Anti-Impact Brackets

In order to effectively alleviate the destructive effect of ground impact on hydraulic supports, a double-layer variable energy absorbing member with higher energy absorption is proposed based on the research basis of single-layer variable energy absorbing components. Based on the energy method to analyze the energy dissipation theory of the expansion and reduction deformation of pipe fittings of different sections, the formula for calculating the bearing capacity of the components in the stable diameter reduction process under different combinations of corrugated tubes and round tubes is derived. Through numerical simulation analysis, the energy absorption curves, bearing capacity curves and deformation laws of eight different types of energy-absorbing components are obtained, and it is found that the double-layer reducer energy-absorbing member structure (SBY type) of the inner bellows and the outer round tube has better energy absorption performance. The influence of different structural parameters on the energy absorption effect was explored, and four structural parameters, namely inner tube wall thickness, outer tube wall thickness, corrugation radius and the number of inversion angles in the base, had significant effects on the energy absorption characteristic parameters. The experimental scheme was designed according to the Latin hypercube sampling method, and the structural parameters were optimized by using the Kriging surrogate model combined with the multi-objective particle swarm optimization algorithm, and finally the optimized structural parameters were selected as follows: inner tube wall thickness 6mm, outer tube wall thickness 2.9mm, corrugation radius 6.9mm, and base inversion angle 40°. The energy-absorbing components were made for axial quasi-static pressurization experiments to verify the accuracy and effectiveness of the simulation analysis and optimization results. The results show that the total energy absorption of the double-layer variable diameter energy-absorbing components is increased by 54.2%, the specific energy absorption energy is increased by 55.6%, the average bearing capacity is increased by 43.2%, and the standard deviation of the load is increased by 59.5%. The designed components have better energy absorption performance, which can make the yield anti-erosion process more reliable, and provide a theoretical basis and reference for the design of energy-absorbing components of deep roadway support hydraulic supports.