Dynamic Response Difference of Hydraulic Support under Mechanical-Hydraulic Co-Simulation: Induced by Different Roof Rotation Position and Hysteresis Effect of Relief Valve

As key supporting equipment in coal mining, hydraulic supports are vulnerable to impact pressure from roof movement and deformation. In this paper, a mechanical-hydraulic co-simulation platform for hydraulic supports is established. Moreover, the rationality of the simulation platform is verified. Based on this platform, the rigid-flexible coupling impact dynamics model of hydraulic support is built. Finally, by delaying the opening time of the relief valve, the energy dissipation problem of the relief valve hysteresis effect on the hydraulic support system under the rotary impact is discussed. The results indicate that the rotary load acting on the hydraulic support decreases gradually with the backward movement of the roof rotary position, which causes the peak pressure in the column to decrease (by 69 MPa). The hinge point load of different parts shows different load transfer laws. The hysteresis effect of the relief valve prolongs the energy release time of the system, increasing the pressure in the column by 23 MPa. The instantaneous opening speed of the relief valve spool reaches 15.7 m/s, and the hinge point between the top beam and the column is most sensitive to the hysteresis effect (impact coefficient increases by 0.63).