一維聲子晶體振動禁帶的理論分析及其實驗研究.pdf

1、蘭州大學(xué)碩士學(xué)位論文一維聲子晶體振動禁帶的理論分析及其實驗研究姓名：花拓申請學(xué)位級別：碩士專業(yè)：力學(xué)工程力學(xué)指導(dǎo)教師：慕青松20090501蘭州大學(xué)碩￡學(xué)位論文AbstractPhononcrystalisanelasticcompositematerialcomposedbydifferentelasticunitsarrangedinaperiodicalsequenceThebandgapappearsaselasticwaves

2、propagateinitTheresearchofthebandgapstructureofthephononcrystalis，therefore，ofgreatimportanceforboththeoreticalstudiesandapplications，andhasarousedgreatconcernamongresearchinstitutionsandscholarsallovertheworldInthispape

3、rtheelasticdynamicanalysismethodisusedtoanalyzethevibrationbandgapsandthedynamicresponseofthefiniteonedimensionalphononcrystalrodTheresultsshowthat：theinteractionsofthephononcrystalmaterialandelasticwavesmakewavesofcerta

4、infrequencieshavenocorrespondingvibrationmodeinperiodicstructures，thatistosaytheyCan’tspread，andtherebybandgapsappearBasedonthis，thecorrespondingdisplacementresponsemodebetweenthebandgapandpassbandisgivenFirstlythefinite

5、elementmethodisadoptedtostudytheperformanceofthelimitedperiodiccompositephononcrystalstructure，andthemathematicalmodelisdiscretizedTheconclusionissamewiththeresultcalculatedfromtheelasticdynamicanalysisSecondlytheinterpr

6、etationofthevibrationbandgapsisgivenintermsofvibrationmechanicsPeriodicstructurescausedtheperiodicchangesofthestiffnessmatrixandmassmatrix，whichinturncausedtheadjustmentofresonancepointsofthephononcrystalsystem，sothatthe

7、reisnesonancepointsinsomecontinuous丘equencydomainsofthewholerangeThusvibrationbandgapsappearBasedonthis，atheoryoftheresonancepointbandgapsdifferentfromtheBlochscatteringmechanismandlocalresonancebandgapsisproposedThelatt

8、icelengththematerialscomponentsratioandtheelasticmodulusanddensityofthetwomaterialsofthephononcrystalstructureisadjustedrespectivelyBycomputationalanalysis，theinfluenceonthesystemvibrationbandgapscausedbythechangeoftheph

9、ononcrystalstructureparametersisobtainedByusingthehome—madesamples，andconductingtestscombinedwithultrasonicdetectortheexistenceofvibrationbandgapsofthephononcrystalisverifiedfromallexperimentalviewpointKeywords：periodics