Abstract

In gas foil bearings, frictional contacts are one of the main factors that affect bearing performance, which is highly nonlinear. Using a finite element method, this article presents a nonlinear model for static performance analysis of foil bearings based on frictional contacts. The model incorporates the top foil and the interactions between bumps by modeling the foil structure with beam elements. The penalty method and the node-to-segment contact scheme are utilized to model the contacts of the structure. The stick–slip motions of the contact nodes are considered. Because the contact behavior is path dependent when the friction is taken into account, a step-by-step incremental iterative method is used for solution, in which the calculation at the present step is based on the results from the previous step. An algorithm is designed to determine the contact states, and the calculation at the next incremental step will not be performed until all contact states meet the check conditions in the present step. To couple the structure domain with the fluid film, each iterative step of the pressure calculation using the finite difference method is regard as an incremental step. This model is validated by comparisons with published results. Using this model, hysteretic behavior caused by friction and dissipative properties of the foil structure are analyzed under static condition.

摘要

在气箔轴承中，摩擦接触是影响轴承性能的主要因素之一，它是高度非线性的。本文采用有限元方法，提出了一种基于摩擦接触的非线性模型，用于箔轴承的静态性能分析。该模型通过使用梁单元对箔结构进行建模，从而合并了顶部箔和凸块之间的相互作用。惩罚方法和节点到段的接触方案被用来对结构的接触进行建模。考虑了接触节点的粘滑运动。由于考虑到摩擦时接触行为与路径有关，因此采用逐步增量迭代法进行求解，其中，当前步骤的计算基于上一步的结果。设计了一种算法来确定接触状态，只有在本步骤中所有接触状态都满足检查条件后，才会执行下一个增量步骤的计算。为了将结构域与流体膜耦合，使用有限差分法进行压力计算的每个迭代步骤都被视为增量步骤。通过与发布的结果进行比较来验证该模型。使用该模型，分析了在静态条件下由箔结构的摩擦和耗散特性引起的滞后行为。使用有限差分法进行压力计算的每个迭代步骤都被视为增量步骤。通过与发布的结果进行比较来验证该模型。使用该模型，分析了在静态条件下由箔结构的摩擦和耗散特性引起的滞后行为。使用有限差分法进行压力计算的每个迭代步骤都被视为增量步骤。通过与发布的结果进行比较来验证该模型。使用该模型，分析了在静态条件下由箔结构的摩擦和耗散特性引起的滞后行为。