Abstract：The force-penetration relationship curver of rocks reflect interaction mechanism beteen the drill bit and rocks in the percussive drilling mechanical system,but the varable characteristics impedamce of a drill bit is essential to obtain the .A new impedance of a drill bit is essential to obtain the curves.new inverse method is proposed to estimate variable characteristics imperamce of the dill bit from the strains in a drill rod using two-point strain measurement and characteristic lines.Firstly,this paper describes stresswave propagation on a rod with variable characteristics impedance and establishes fht time and space analysis equations using a grid of chatacteristics lines.Secondly,a new inversion principle is proposed to calculate the variable characteristics impedance of drill bit in turn,according to a state vector at one point of the rod,and a method is introduced to calculate the state vector at any point suing two-point strain of the rod.Finally,the inversion meahod using two point steain of the rod and characteristic lines is validated and discussed,which can estimate variable characteristics impedance of the bit.
刘德顺;何先可;段 凯. 基于特征线的杆波阻特性两点应变法反演研究[J]. , 2011, 30(2): 69-72.
Liu De-shun;He Xian-ke;Duan Kai. Study on Inversion of Characteristics Impedance of the Bit Using Two-point Strain Based on Characteristic Lines. , 2011, 30(2): 69-72.
2011, Vol. 30 
