拉杆结构非线性接触的刚度融合修正方法

Fusion Stiffness Modification of Spring and FE Modal in Rod Fasten Rotor Base on Non-linear Contacting Model

为建立更加准确的航空发动机高压转子的有限元模型,对表征高压转子拉杆结构中盘与盘之间接触的力学模型进行研究,引入包含库伦摩擦力的非线性弹塑性滑动模型对该类接触进行描述。提出弹簧刚度矩阵和有限元模型整体刚度矩阵的融合修正方法,建立了有限元刚度的整体优化模型。运用拉直算子将模型中需要修正的参数分离出来,结合实验模态参数对有限元模型刚度进行了修正。以实际航空发动机高压转子为例,通过与线性模型的修正结果比较,证明该模型准确描述了拉杆结构的复杂接触,且融合算法是可行且有效的。

The scope of this paper lies in FE （finite element） modal updating of high pressure spool in aero engine. By examining the mechanical modals which describe the contacting surfaces between the wheel disks of rod fasten rotor in high pressure spool,it introduced the elasto-slip model with non-linear hysteretic behavior to describe the complex contacting surface. A total optimization modal is developed for a FE modal stiffness updating using a fusion method which combines the modification of stiffness of local parameters and of global modal together. The calculation of the optimization modal is to employ straighten algorithm to extract the parameters which needed to be calibrated, and to modify them with modal parameters got by experimental modal analysis. Results of this fusion modification to real high pressure spool and comparison with linear mechanical modal are given to illustrate that the elasto-slip model and fusion stiffness modification truly represent the contacting state of high pressure spool.