煤岩瓦斯动力灾害冲击波作用下防突风门失效机理

Failure mechanism of anti-outburst ventilation door under impact of coal-rock gas dynamic disasters shock waves

  • 摘要: 防突风门是保持通风系统稳定的关键构筑物,当煤岩瓦斯动力灾害发生时,形成的强烈冲击波在传播过程中会破坏防突风门,导致瓦斯逆流和瓦斯积聚现象,甚至会诱发二次灾害。为了研究煤岩瓦斯动力灾害冲击波作用下防突风门的失效机理,以冲击波的超压−冲量理论为核心,建立防突风门屈曲失效的超压−冲量理论模型(P-I理论模型),利用LS-DYNA软件模拟防突风门在冲击波作用下的动态响应规律,并将模拟得到的风门的破坏情况和风门屈曲失效的P-I理论模型进行对比。结果表明:煤岩瓦斯动力灾害冲击波导致风门失效的根本原因是冲击载荷产生的超压和冲量使风门的响应形式发生变化;在灾害冲击波作用下,风门的薄弱位置在门扇中心区域、门扇与门框的连接处;当初始瓦斯压力超过1 MPa时,10 mm厚的Q235钢质风门发生屈曲失效,不同厚度风门的等效应力、位移、速度、能量场分布具有相似性,风门的厚度越大,在相同冲击载荷作用下获得的等效应力、位移、速度、能量越小,抗灾能力越好,且高强度的钢材料抗冲击性能更好;数值模拟结果和屈曲失效P-I理论模型对风门失效情况的判定结果一致,P-I理论模型可以用来判定防突风门是否发生屈曲失效;以风门材料的屈服极限为判定依据,建立了防突风门屈曲失效的极限状态方程,当极限状态方程大于0时,防突风门发生屈曲失效。研究结果为井下防突风门的安设和煤岩瓦斯动力灾害的防治提供了理论指导。

     

    Abstract: Anti-outburst ventilation doors are the key structures to maintain the stability of the ventilation system. After a coal-rock gas dynamic disaster, the anti-outburst ventilation doors are subjected to significant impact forces and are prone to failure. If the ventilation doors fail, gas backflow, which can severely trigger secondary disasters. To study the failure mechanism of anti-outburst ventilation doors caused by the shock waves of coal-rock gas dynamic disasters, a P-I theoretical model for the buckling failure of ventilation doors is established with the overpressure-impulse theory of shock waves as the core. The LS-DYNA finite element software is used to simulate the dynamic response of ventilation doors under the impact of shock waves. And compare the damage situation of the ventilation door obtained from the simulation with that obtained from the P-I theoretical model. The results show that: the root cause for the failure of ventilation doors caused by the shock wave is that the overpressure and impulse generated by the impact load alter the response mode of the ventilation doors; the weak areas of ventilation door are in the central area of the door panel and at the connections between the door panel and the door frame; when the initial gas pressure is more than 1 MPa, the 10 mm thick Q235 steel anti-outburst ventilation door experiences buckling failure; the distribution of equivalent stress, displacement, velocity, and energy fields for ventilation doors shows similarities in different thickness; as the thickness of the ventilation door increases, the equivalent stress, displacement, velocity, and energy under the same impact load decrease, resulting in improved resistance to disasters. And higher-strength steel materials exhibit better impact resistance. The determination of ventilation door failure in the numerical simulation is consistent with the results obtained from the P-I theoretical model. The P-I theoretical model can be used to determine whether ventilation doors experience buckling failure. Using the yield limit of the material as the criterion, a limit state equation for the buckling failure of ventilation doors is established. When the limit state equation is greater than 0, the ventilation doors undergo buckling failure. The results provide theoretical guidance for installing anti-outburst ventilation doors and preventing coal-rock gas dynamic disasters.

     

/

返回文章
返回