文档介绍：摘要随着水电事业的不断发展,电站单机容量和厂房尺寸不断增大,由此可能引发的水电站厂房结构的振动问题非常令人关注,特别是厂房流道内的脉动压力引起的结构振动值得研究。本文结合喜河水电站工程,对水电站厂房机组支承结构的模态特性、机组水力振动振源、流道内脉动压力特性、机组支承结构在各种动荷载作用下的动力响应等几方面问题进行了较全面的分析研究。其中对脉动压力的考虑方法颇具新意。用有限元法重点计算分析了水电站厂房支承结构在各种不同情况下的动力特性;通过对比分析,深入研究了各个因素对厂房支承结构动力特性的影响;对水电站厂房支承结构的振源进行了分析,根据分析结果进行了共振校核,并针对共振校核中出现的问题,提出了几点建议;结合水电站厂房流道内脉动压力的自身特性,参照已有水轮机流道内压力脉动分布规律的研究成果,对厂房支承结构整个流道内脉动压力分布做出了合理假设,并根据脉压时程曲线进行了频谱分析,得到脉动压力的优势频率;通过分析和计算,确定了两种对厂房支承结构振动产生重要影响的典型动荷载,并用不同方法计算出了水电站厂房支承结构在这两种典型动荷载作用下的动力响应值。水电站厂房支承结构自振频率与整体厂房自振频率相比偏高,但相对应的自振特性仍保持一致;水电站厂房支承结构自振特性的几个主要影响因素中,楼板的边界条件和附加质量影响较大;水电站厂房支承结构可能与蜗壳中不均匀流场引起的激振力、压力钢管一水轮机水道系统的水击激振力和不均衡磁拉力引起的激振力发生共振:频谱分析表明水电站厂房支承结构流道内的脉动压力主要体现为低频水力激振力,其中蜗壳内的脉动激振力有可能与厂房支承结构发生共振。【关键词】水电站厂房、支承结构、振动特性、脉动压力、振源 Abstract With thedeveloping ofhydro-electrical enterprise,the singledynamo capacity andscaleof theplant are growing,which may cause vibrationproblems ofthepowerhouse structure,and the vibration problem has been given anemphasis ,the vibration induced by fluctuating pressure inthe tunnel ofhydropower plant isworthy the supporting structure ofXiho hyaropower plant asanexample,some problems suchas themodal characteristic ofhydropower plant supporting structure,the vibration sources ofhydraulic generators,the characteristics offluctuating pressure intunnel,and thedynamic response of supporting structure under different kinds ofdynamic loadsareinvestigated isan innovation totakefluctuation pressure ount. The finiteelementmethod isapplied toanalyze thedynamic characteristics ofsupporting structure under different on parison andanalysis of thestudying results,the factorsinfluencing thedynamic characteristics addition,vibration source ofhydropower plant supporting structure totheanalyticalresults, theresonance iscalibratedand afew pieces ofsuggestion are put forward inthelight ofthe problems occurred duing the resonance 、析tllthe own features of fluc