基于Hypermesh和Ansys的卧螺过滤离心机转鼓系的模态分析

卧式螺旋过滤离心机的转鼓系作为整机振动的振源,是研究离心机动载荷与机械振动的重点对象。结构共振与物料分布不均是转鼓系振动的主要原因。对转鼓系进行有限元模态分析,可以避免结构共振的发生。通过UG建立了转鼓系的几何模型,并利用Hypermesh对几何模型进行了六面体网格划分。采用接触对与MPC算法,实现了零部件之间不连续网格的连接。基于BlockLanczos算法,在Ansys中对转鼓系有限元模型进行了特征值提取,得到了转鼓系在有、无离心预应力下的前8阶固有频率与振型。研究表明,转鼓系在给定工作转速下,不会发生结构共振。离心预应力对固有频率的低频成分影响较大,而对中高频成分影响较小。研究结论为整机瞬态动力学分析与转鼓系结构优化研究与设计提供了依据。

The Modal Analysis of Drum System for Horizontal Worm Screen Centrifuge Based on Hypermesh and Ansys

Drum system of the horizontal worm screen centrifuge as the vibration source of the whole machine is the key study object of the centrifuge′s dynamic load and mechanical vibration.Structural resonance and material uneven distribution are the main causes of vibration of the drum system.The structural resonance can be avoided by modal analysis for the drum system using finite element method.The geometric model of drum system is founded by UG,then it is partitioned by hypermesh using hex grid meshing method.Contact pair and MPC(multipoint constraint) algorithm are used to achieve a connection between two components with discontinuous grids.The eigenvalues of drum system are extracted in ansys based on block lanczos algorithm and the solution offers the first eight natural frequencies and vibration modes of the drum system under both the conditions with and without centrifugal prestress.The results demonstrate that the structural resonace will not occur at the rated working speed.The centrifugal prestress has an obvious effect on the lower natural frequencies.The conclusions provide the basis for research and design on the transient dynamic response of the whole machine and the structure optimization of drum system.