水电站厂房楼板自振特性研究

为分析某坝后式水电站厂房结构自振特性,开展现场模态试验和有限元数值模拟计算,并对比两种方法的差异性,同时探讨了厂房剧烈振动原因。结果表明,针对振动突出的局部区域,两种方法自振频率及振型基本一致,可认为数值计算结果真实可靠;数值计算中,除直接对结构整体进行模态计算和谐响应动力复核外,还可针对研究重点进行局部模态分析,以避免因整体计算而产生的频率及振型的掩盖现象。

Research on Self vibration Characteristics of Floor Slab Structure of Hydropower Station

The natural vibration characteristics and the difference between the field model test and finite element analysis are calculated for a powerhouse structure of hydropower station at dam toe. At the same time, the causes of severe vibration of powerhouse are analyzed. The results show that the natural frequencies and modes in the local area where vibration is prominent obtained by FEM are in agreement with the field model test. Besides the modal calculation of the whole model and the resonance check with harmonic analysis, the modal calculation for the key local area is proposed in order to avoid masking vibration modes and frequencies.