大坝底孔弧形闸门原型振动试验研究

本文介绍了万安水利枢纽大坝底孔弧型闸门原型模态分析的方法和测得的前12阶模态及其频率和阻尼,还给出了闸门在泄洪时的振动实测资料。实测表明闸门的模态比较密集,支臂频率比门页低。在下游淹没条件下泄洪,发生强烈振动是难免的。振动观测表明,闸门在下游淹没状态下泄洪时振动强烈,并有明显的优势频率,与闸门自频率接近,运行中应力求避免这种工况。

Prototype study on bottom sluice tainter gate Vibration

A Bottom sluice tainter gate of a dam is usually used for regulating flood discharge. In flood season when submerged discharge becomes unavoidable. the gate may suffer flow-induced vi- bration. At Wan'an project the bottom sluice tainter gate of the dam has dimensions of 9. 5 m high, 7m wide and 18 m radius. The prototype vibration study on it including vibration mode test and flow --induced vibration measurement has been carried out. The vibration mode of tainter gate has two types: rotational oscillation about pivot and structure vibration. The latter type is of structure elastic vibration. The structure of the gate consists of tree substructures: gate leaf and two arms. each one has its own vibration mode, and these modes couple with each other and form an integral vibration mode. Hammering method is used to obtain transfer functions. CRAS software is used for substruc- ture and integral mode analysis. The prototype vibration stimulated by hammering, relevant mea- sured dynamic characteritics as well as the mode test analysis are presented in this paper. The study shows that the tainter gate suffers significant vibration during submerged discharge when the ampli- tude of vibration at gate arms are considerably large and on the other hand the gate flow-induced vi- bration is rather slight during non-submerged discharge.