103 / 2021-09-29 18:24:24

Dynamic response analysis of four leg hydraulic support under impact load

impact load,dynamic response,variable stiffness,four leg hydraulic support

Hydraulic support is the key supporting equipment in fully mechanized mining face. Frequent impact load in coal mining is one of the key factors causing support instability. In order to improve the support stability of four leg hydraulic support, this study discusses the force transfer characteristics of each hinge joint and the vibration characteristics of the leg system when the canopy and goaf shield of the hydraulic support bear the impact load at the same time. Firstly, the canopy, goaf shield and front and rear bars are flexible. Then, the rigid flexible coupling numerical analysis model of the support is established by using ADAMS software. The leg of the model is replaced by the equivalent spring variable stiffness system. The initial support force of the support is provided by two active external loads at the canopy, the load direction is perpendicular to the canopy downward, and the impact load is applied vertically to the canopy and goaf shield along the central symmetry plane of the support. Finally, the mechanical response of each hinge joint of the support under impact load at different positions is analyzed. The results show that the hinge joint of the support shows different response characteristics to the impact load at different positions. When the front end of the canopy is loaded separately, the load variation coefficient of the front leg is as high as 1.4, which has the greatest impact on the stability of the support. The load variation coefficient of the hinge joint between the canopy and the goaf shield reaches 2.4 when the canopy and the goaf shield are loaded at the same time,which is the most sensitive to impact load. The research is helpful to the mechanical structure design of hydraulic support and improve the stability of support.