用接触有限元研究胶筒系统的力学行为

Study mechanical behavior of packer element systems with contact FEA

为了研究封隔器胶筒系统的力学行为,文章应用ANSYS的参数化设计语言APDL(ANSYS Parametric De-sign Language),编制了胶筒系统的接触有限元命令流。研究了轴向坐封载荷与胶筒的峰值接触压力和轴向压缩量之间的变化规律。根据胶筒的变形特征,其力学行为可以分为A、B、C三个基本阶段。用接触有限元方法详细研究后发现,每一个基本阶段又可细分为若干小阶段,例如B1、B2。根据这些小阶段的特点,可以确定封隔器胶筒的最小坐封载荷等于B2小阶段结束处的轴向坐封载荷。当轴向坐封载荷达到C3阶段的末点时,设计胶筒防“肩突”结构是必须的,否则容易出现胶筒失效。

In order to study the mechanical behavior of packer element systems, this paper presents the application of ANSYS Parametric Design Language （APDL） and the use of the contact FEA programs. The laws between axial set-down loads and maximum contact sealing pressure, and axial compressed displacement were studied. According to features of deformed packer elements, the mechanical behavior can be classified three basic stages. Finer stages can be found in every basic stage by studying contact FEA in details. On the basis of these fine stages, the minimum axial set-down loads can be determined at the end of B2 stages. When the axial set-down loads reached or overrun at the end of C3 stage, the structure preventing from＂shoulder upwarping＂of packer elements should be designed, otherwise, failure of packer elements would occur.