深井冲击载荷下液压支架底板比压分布特性

液压支架的自移性能是保障工作面安全高效生产、提升工作面智能化开采水平的重要因素,而影响液压支架自移性能的关键因素之一即为其底板比压分布特性。为研究冲击载荷作用下深井开采液压支架的底板比压分布特性,首先基于多体动力学分析软件ADAMS建立了液压支架整架的刚柔耦合数值分析模型,其中顶板与底座定义为刚性体,顶梁、掩护梁、四连杆结构处理为柔性体,立柱及平衡千斤顶采用弹簧阻尼系统等效替换。通过在液压支架顶梁上方不同位置分别施加冲击动载,获取了液压支架在不同冲击工况下底座柱窝和前后连杆铰接点处的冲击载荷响应谱。随后基于LS-DYNA软件建立了液压支架底座-底板柔性体数值分析模型,通过将获取的各工况下支架载荷响应谱分别输入底座-底板柔性体分析模型,研究了深井开采液压支架在不同冲击工况下的底板比压分布规律。结果表明,在各冲击工况下液压支架的底板比压均未呈现线性分布形态,而是呈前端沉陷-中部压入-后端翘曲的“V”型分布,其中比压峰值点分布于柱窝附近,且虽然作用于液压支架的冲击载荷形式不一,但在满载失稳条件下支架底板比压危险区域均出现在底座前半部分;冲击载荷出现前后并未改变底板比压的分布特征,但会促使支架各铰接点力响应及底板比压瞬时峰值升高,从而恶化液压支架-底板的耦合状态,不利于工作面底板维护及移架操作,因而深井开采液压支架更应注重其底座结构的设计优化,以降低支架前端比压分布,提升支架的支护稳定性及自移性能。

Analysis of distribution characteristics of study on floor specific pressure of hydraulic support for deep mining based on impact loading

The self-advancing performance of hydraulic support is an important factor to ensure the safe and efficient production and improve the intelligent level of the coal mining working face.One of the key factors that affect this self-advancing performance of hydraulic support is its floor specific pressure distribution characteristics.In order to study the floor specific pressure distribution characteristics of the hydraulic support in deep mining under the impact loading condition,a numerical model based on the rigid-flexible coupling of the support is established by using ADAMS.The roof and the base were defined as rigid,the canopy,the goaf shield and lemniscate bars were meshed as flexible,and the legs and equilibrium jack were replaced using the spring damping system.By applying impact load to different positions above the canopy,the response spectrum of the impact load at hinge point of the socket and the lemniscate bars was obtained.Then a numerical model of the base-floor flexible body was established by using LS-DYNA.By inputting the obtained load response spectrum into the base-floor flexible model respectively,the distribution law of the floor specific pressure under different impact conditions was analyzed.The results show that the floor specific pressure is not linearly distributed,but presents a“V shaped”distribution.The peak value of the floor specific pressure is distributed near the socket.Although the impact loads acting on the hydraulic support are different,the dangerous area of the floor specific pressure appears in the front half of the base under the condition of full load instability.When the impact load appears,both the force response of each hinge point and the peak value of the floor specific pressure will increase.This will further worsen the coupling state between the base and floor,and of course is not conductive to the floor maintenance and moving operation of the base.Therefore,in order to reduce the pressure distribution at the front end of the base,and improve the support stability and self-advancing performance of the support,it is necessary to pay more attention to the optimization of the base structure in deep mining.