钻柱弯曲振动的工程计算方法

建立直井中任意多扶正器组合钻具的弯曲振动力学模型,并采用集中质量法将钻柱质量离散化,以便于计算和程序的实现。引入描述钻柱弯曲振动的状态向量,采用传递矩阵法建立钻柱系统中各截面状态向量间的一般关系,从而推导出计算钻柱弯曲振动固有频率的特征方程和振型状态向量的基本算式。编制出可同时计算出钻柱弯曲振动各阶振动频率,以及相应的任意截面的变形、弯矩和剪力等的BFVDS通用计算程序。

Computer Program for Calculating the Bending Vibration of Drillstrings

This article establishes a mechamcal model of the bending vibration of a drill stem assembly with multi-stabilizers in a straight hole. With the help of the lumped mass method and the transfer matrix method, the article sets up the general relation between the state vectors at different cross sections of the drillstring system, and, finally, works out the BFVDS general purpose computer program, which can be used to compute the bending vibration frequencies, and, at the same time, the deformation, bending moment and shear force at any corresponding cross section of the drillstring.