流固耦合下金属波纹管应变及模态分析

以S形金属焊接波纹管为研究对象,针对密封腔流体及预应力耦合激励诱发波纹管振动失效问题,建立了机械密封的耦合模型;对比分析流体和预应力对波纹管模态的影响,得到了波纹管在不同工况下的振型、自振频率和等效应变。结果表明:波纹管模态在外部流场作用下变化较明显,预应力几乎不影响波纹管固有频率;流场压力恒定时,增大转速和预应力,波纹管等效应变减小;随着流体进口压力增大,波纹管的最大等效应变和应力增大。研究结果为机械密封失效机制和波纹管结构优化设计提供了理论依据。

Strain and Modal Analysis of Metal Bellows Considering Fluid solid Interaction

Taking the S-type metal welded bellows as the research object, a coupling model of mechanical seal was established aiming at the problem of vibration failure of bellows induced by fluid and prestress coupling excitation in the seal cavity; the vibration mode, natural frequency and equivalent strain of bellows under different working conditions were obtained by comparing and analyzing the influence of fluid and prestress on the mode of bellows. The results show that the modal of bellows changes obviously under the action of external flow field and the prestress hardly affects the natural frequency of bellows; when the flow field pressure is constant, the equivalent strain of bellows decreases with the increase of speed and prestress; the maximum equivalent strain and stress of bellows increase with the increase of inlet pressure of fluids.The conclusion provides a theoretical basis for the failure mechanism of mechanical seals and the optimization design of bellows.