Study on the mechanical properties and energy dissipation characteristics of polymer-coated coal samples under coupled static-dynamic loading
ZHAO Yixin
YANG Zhe
GONG Zhixin
ZHAO Bowen
Abstract：To investigate the influence of polymer coating support on the impact resistance of coal,this study aims to reveal its mechanical characteristics and energy dissipation behavior under coupled dynamic-static loading.Split-Hopkinson Pressure Bar(SHPB)system,coupled dynamic-static loading tests were conducted on coal samples prepared with three different poly-mer coating thicknesses:0 mm(uncoated),1 mm,and 2 mm.The samples were first subjec-ted to a constant hydraulic oil pressure of 0.25 MPa,followed by five low-energy cyclic im-pacts(driven by 0.2 MPa air pressure)and one high-energy impact(driven by 0.3 MPa air pressure).The experimental results indicate the following:Mechanical Characteristics:The polymer coating significantly enhanced the dynamic peak stress and peak strain of the coal sam-ples,thereby improving their dynamic strength and deformation capability.Compared to the uncoated samples,the peak strain and peak stress of the 2 mm coated sample under high-ener-gy impact increased by approximately 54.65％and 44.69％,respectively.Additionally,the coating layer reduced the dispersion of the stress-strain curves during cyclic impacts,indicating a more stable mechanical response.Energy Characteristics:The coating layer improved energy coupling properties by reducing the proportion of reflected energy while effectively increasing the proportion of dissipated energy.This also resulted in more stable energy dissipation under cyclic impacts.Under high-energy impact,the reduction in dissipated energy for the 2 mm coated sample was only 11.51％,significantly lower than the 24.31％observed in the uncoated sample,demonstrating superior impact resistance.Failure characteristics:The polymer coat-ing effectively suppressed the degree of fragmentation.As the coating thickness increased,the specimen integrity was significantly enhanced.The mass ratio of detached coal fragments de-creased from 0.54(0 mm coated sample)to 0.01(2 mm coated sample).In conclusion,the polymer coating effectively improves the overall load-bearing capacity and impact resistance of the coal body,significantly enhances its energy dissipation capability,and transforms the vio-lent impact failure into a more gradual energy release process.This holds positive implications for the prevention and control of coal bursts.
Keywords：SHPBstatic-dynamic coupling loadingthin spray supportmechanical propertyenergy dissipation
Publication Date：2025-11-30
Online Publishing Date：2026-01-09(First online date of this platform, not the publication date of the document)
Pages：15( 1401-1415 )