基于特征线的杆波阻特性两点应变法反演研究

摘要

The force-penetration relationship curves between a drill and rock reflect interaction mechanism between a drill bit and rock in a percussive drilling mechanical system, but the characteristic impedance of the drill bit is essential to obtain these curves.A new inverse method was proposed to estimate the characteristic impedance of the dill bit using two-point strain measurement and characteristics lines.Firstly, the stress wave propagation in a varying characteristic impedance rod was described and the time and space analysis equations using characteristics lines were established.Secondly, a new inversion principle was presented to calculate the characteristic impedance of the drill bit according to a state vector at one point of the rod, and a two-point strain measurement method was introduced to calculate a state vector at any point with the strains of two points of the rod.Finally, the inversion method using two-point strain measurement based on characteristic lines was validated and discussed.%在冲击凿岩机械系统中,钻头对岩石的作用力与凿深的关系曲线反映了钻头与岩石相互作用机理,而钻头波阻特性是获取这种关系曲线的前提.提出了一种基于特征线和两点应变测试法来反演计算钻头波阻的方法.首先应用特征线网格,描述应力波在变波阻杆中的传播规律,分别建立依空间和依时间波动分析方程;然后提出了根据弹性杆上一点状态矢量依次计算钻头波阻的反演原理,介绍了由弹性杆两点应变求解任意一点状态矢量的方法;最后对基于特征线的杆波阻特性两点应变反演方法进行了验证和讨论.