Chock-shield support is usually used in undergroud coal mining to protect the roof. However, as the mining depth gets deeper, impact load that came from the roof becomes stronger and more frequent. This causes the support to bear a large number of dynamic loads, and reducing its reliability. To improve the support performance of the chock-shield support, the mixed-kinetic model was established using the mechanical-hydraulic co-simulation method. The load distribution law of the support joint under impact load form different stability forces, impact load amplitude, and impact frequency is discussed. The mechanical-hydraulic cooperative response of the chock-shield support are obtained. The results show that different joints show typical non-uniformity characteristic during the loading process. The proposed mechanical-hydraulic co-simulation method can more accurately obtain the dangerous points of hydraulic support reliability. The results of this study will help to improve the reliability of the chock-shield support.

Hydraulic support is a collaborative bearing equipment with hydraulic transmission power and mechanical bearing load. The method of the mechanical-hydraulic co-simulation model is used to discuss the response difference of hydraulic support in the process of roof rotation. Based on this model, the variation law of hydraulic support is analyzed by changing the rotation velocities of the roof. Then, by changing the discharge flow of relief valves at the column, the energy unloading characteristics of the column are discussed. The results demonstrate that with an increase in the roof rotary velocity, the pressure and flow peaks of the column increase continuously (the increase multiples of pressure and flow peaks are 123% and 51%, respectively). The tendency of load variation at different locations of hinge points appears to be varied. Lastly, this paper increases the discharge flow of the relief valve to shorten the energy unloading time (by 1.5 s) and reduce the load at the hinge point. This approach helps reduce the probability of damage to the hydraulic support and prolongs its life.

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).