Research On Vibrationg Structure Of Spiral Case Using Cushion Layer

Along with spiral case using cushion layer be more and more been applied in each domestic and international big and medium-sized hydroelectric station, motive characteristic of structure of spiral case using cushion layer drive more and more people regard, because of steel plate and concrete have a soft mat layer to save greatly in structure of spiral case using cushion layer ,which make function of restriction of the concrete steel shell a to lower, may cause the disadvantageous influence when unit is circulating. That is one of the important questions which choose a spiral case using cushion layer. In the past although the domestic once did a great deal of research about structure of spiral case using cushion layer, scarcity analysis of motive characteristic, therefore study about motive characteristic of structure of spiral case using cushion layer need to solve urgently in hydraulic engineering.Architectural motion differential equation the main body of a book is deduced out taking Hamilton (Hamilton) principle as the basis. Solved particular certain structure to encourage in the outside power ,the motive of the structure responds to a problem .And under not having the outside force excitation, the structure proper and dynamical characteristic problem, study the vibration source in hydropower plant, and resonance checking is given to the spiral case using cushion layBesides, the main body of a book try to imitate by numerical value , take some's projects as the example secretly scheming against , change bed course condition and the snail shell structure form respectively , carry out analysis on the architectural snail shell self vibrate characteristic property setting up a bed course. The result when selecting and using the material being unlike a bed course's and adopt the range that the be unlike bed course lays, secretly scheming against is indicated , is enhance but is changed into the architectural snail shell self vibrate frequency meeting with putting in tier of the material elasticity moduli's big, under lay cospecific bed course material but lay range's with different bed course situation, architectural snail shell self vibrate frequency will be with the bed course laying range enhancing but diminishes; But in changing the snail shell structure form, the result respectively, changing the steel snail shell outer-ring concrete's when concrete thickness and the steel snail shell diameter, secretly scheming against indicates, concrete that snail shell structure will be from shaking frequency's with steel snail shell outer-ring concrete thickness's be thickened by but change big, architectural snail shell self vibrate frequency will be small with steel snail shell diameter unexpected turn of events but enhances when adopt the same concrete to irrigate thickness as if it be the steel snail shell outside.