球面冲击波作用下船体梁整体运动的简化理论模型

为了研究水下爆炸冲击波作用下,船体结构的局部变形以及局部变形引起的船体整体运动响应, 将船体简化为理想刚塑性等截面直梁,考虑流固耦合效应,推导了梁所受冲击波载荷的理论计算公式,并进行 了试验修正。以炸药在船体中部正下方爆炸的工况为研究对象,将球面冲击波作用于船体的过程,简化为一 系列移动、短时的局部平面波加载过程的叠加,提出了一种计算船体梁在任何爆距条件下发生总体塑性运动 响应的理论方法,最后利用船体梁模型试验对该方法进行了验证。结果表明:所建立的冲击波作用下船体梁 整体运动响应模型能够反映船体梁结构在冲击波作用下的塑性运动过程;在冲击波作用时间内,以船体梁中 点的运动情况为例,其存在先向上、后向下的往返运动过程;与造成的局部变形相比,冲击波造成梁整体运动 变形的作用较小。

A simplified theory model of ship-like beams'bulk movement subjected to spherical shockwaves

Asamainenergyreleasefromunderwaterexplosion,blastcancauselocaldistortionofwarshipstructure, whereas,howthehullwillactagainstshockwavedeservesanadvancedresearch.The hullwassimplifiedasarigid,perfectlyplasticuniformbeamfloatingonwater.Theformulaofthe wallpressureonthewetsurfaceofthebeam wasattainedandmodifiedaccordingtotestdatawhere thefluid-structureinteractionwasconsidered.Inordertostudydynamicresponseofship-likebeams subjectedtounderwaterexplosionlocatedcloselyunderthemid-spanofthebeam,ahypothesiswas putforwardthatthesphericalshockwavespreadingonthehullwascomposedofaseriesofmoving, instantaneous,localplaneshockwaves,andtheresponseofthebeamsubjectedtosphericalshockwave wasequivalenttointegralresponsesduetoalltheplaneshockwaves.Basedonthissimplification,a theoreticalmethodwasproposedtodescribehowthebeamactedagainstunderwaterexplosionatany standoff.Finally,thetwomodelsofship-likebeamswereusedintheteststoverifytheproposed method.Resultsshowthatthetestdatabasicallyagreewiththoseoftheoreticalanalysis.Duringthe durationofshockwaveloadingonthebeam,themid-spanofthebeamtakesaback-and-forthmovement. Shockwavesplayasmallerroleinmakingbeamsbulkmovementthanthatincausinglocaldistortion.