综合预应力与陀螺效应的TLJ500土工离心机模态分析

目的分析获得离心机运转时各综合效应对其模态频率的影响。方法从理论上推导结构在无离心场时,仅考虑预应力刚化效应和仅考虑旋转软化效应与综合考虑各效应时结构固有频率之间的关系。建立TLJ500土工离心机静止状态及运转状态的有限元模型,并根据TLJ500静止状态的模态试验结果对有限元模型中主轴轴承部位的材料参数进行修正识别,获得可信度更高的模型。再将修正识别得到的主轴轴承参数代入离心机运转状态的有限元模型,开展离心机运转状态的模态分析,结合理论分析结果,计算得到综合考虑预应力刚化效应与旋转软化效应时离心机关心模态频率的结果。结果运转状态TLJ500离心机关心模态频率计算结果与试验结果比较一致。结论仿真结果验证了文中方法的可行性,为离心机临界转速设计提供了一种可信的数值模拟预测方法。

The Modal Analysis on the TLJ500 Centrifuge with the Pre-stress and Gyroscopic Effect

This paper aims to get the influence of various comprehensive effects on the modal frequency of the centrifuge during operation. Firstly, the natural frequency relationship about synthetically effect, no effect, only pre-stress effect and only gyroscopic effect is established in theory. Then, the finite element (FE) model of the TLJ500 centrifuge is built, and the elastic modulus of the bearing is identified by the FE model updating based on the modal test results when the centrifuge is not working. Next, the elastic modulus of the bearing in the centrifuge FE model with working is replaced by the identifying result, and the modal analysis is carried out. Lastly, the natural frequency of the TLJ500 centrifuge with the pre-stress and gyroscopic effect is calculated by combining the FE simulation results and the theory equation. The synthetically calculating results agree with the experimental results better when the centrifuge is working, which proves the feasibility of the proposed approach, and which can be used to calculate the more believed critical speed of revolution when designing the centrifuge.