一种在ANSYS中模拟磁流变液的方法

A Method to Simulate the MR Fluid in ANSYS

磁流变液在零场时,符合牛顿流体的力学特征,在ANSYS中可用流体单元FLUID142模拟。而处于磁场作用下的磁流变液还呈现出一定的类固体特征,在ANSYS中尚无完全合适的单元进行模拟。本文提出一种在ANSYS中模拟磁流变液在屈服前阶段力学行为的方法,即重合单元法,主要思想是采用重合的两种单元分别模拟磁流变液的流体特性和粘弹性固体特性。以一磁流变液夹层简支梁为研究对象,采用本文提出的分析方法对其进行有限元计算,通过与文献[1]的理论分析及实验研究结果比较,本文方法所得结果与之相近,验证了本文有限元分析方法的有效性。在目前尚无完全合适单元模拟磁流变液的情况下,这种方法为带有磁流变液夹层(或磁流变阻尼器)的结构有限元分析提供了可行的途径,对以后开发相关的ANSYS单元,也有一定的借鉴作用。

The magnetorheological fluid（MRF） is consistent with the mechanical properties of Newtonian fluid when no external magnetic field is present,at this time it can be modeled using FLUID142 in ANSYS.However,when exposed to a magnetic field,the MRF is also showing some solid-like characteristics,at present,there is no exactly appropriate element type in ANSYS to model MRF.This paper presents a method to simulate the mechanical behavior of magnetorheological fluid subjected to magnetic field in the pre-yield region in ANSYS.The main idea is devide an MRF element into two coincident elements,one of them has density and viscosity without shear modulus while another has shear modulus without density and viscosity.Take a simply supported MRF sandwich beam as an example,comparing the results with the theoretical analysis and experimental study of Ref.[1],this method can obtain good results and reasonable conclusion,verified the validity of finite element analysis in this paper.This kind of method which can be called Coincident Elements Method provides a new way to model the structures with MRF or MR dampers in ANSYS,and it also has some inspiration for the future development of related elements in ANSYS.