振动采气管柱应力强度分析

为了给采气管柱疲劳寿命分析和完整性分析提供依据,考虑管柱自重及内、外压沿深度的线性变化,用有限元软件分析振动采气管柱的应力强度。将采气管柱看作是内空的细长杆,用有限元法对管柱进行离散化处理,再用拉格朗日方程得到采气管柱动力学微分方程。采用二维轴对称模型进行建模,采用4节点平面单元Plane42进行分析。分析结果表明,采用ANSYS中轴对称单元Plane42建立采气管柱有限元模型,进行振动采气管柱的应力强度分析是一种有效的方法;井口管柱应力最大,是应力危险点;振动载荷作用下,管柱内壁所受应力大于外壁所受应力。

An Analysis of the Stress Strength of Vibration Gas Recovery Pipestring

To provide the basis for the fatigue life analysis and completeness analysis of gas recovery pipestring,the finite element software was used to analyze the stress strength of vibration gas recovery pipestring considering the dead weight of the string as well as the linear change of internal and external pressures along the depth.Regarding the string as the slender rod which is internally hollow,the finite element method was used to conduct a discretization treatment of the string.Then,the Lagrange equation was adopted to obtain the dynamic differential equation of the string.The two-dimensional axisymmetric model was adopted to conduct modeling and the four-node plane unit Plane42 was applied to conduct an analysis.The analysis shows that it is an effective method to adopt the axisymmetric unit Plane42 of the ANSYS software to establish the finite element model of the gas recovery string and to make a stress strength analysis of the string.The maximum stress is with the wellhead string,which is the dangerous point of stress.The stress of the inner wall of the string is greater than that of the external wall under the effect of vibration load.