摘要:
针对水下爆炸载荷、瞬态流固耦合效应在舰船水下爆炸数值模拟中的困难,在现有水下爆炸载荷
计算模型(GeersandHunter)的基础上,结合边界元法,修正水下爆炸气泡载荷计算方法。针对用二阶双渐近
法(thesecond-orderdoubly-asymptoticapproximation,DAA2)在处理低频大幅运动流固耦合问题时的局限
性,提出非线性双渐近法(nonlineardoubly-asymptoticapproximation,NDAA),计入了舰船大幅低频运动、自
由面效应等非线性因素,并与结构有限元程序相结合,形成一套适合于工程应用研究的舰船水下爆炸数值模
拟程序。数值模拟结果与实验结果的平均误差在16.8%左右,说明NDAA 方法可为冲击波和气泡对舰船结
构毁伤数值模拟提供参考。
Abstract:
Aimedatthedifficultiesofunderwaterexplosionloadandinstantaneousfluid-structureinteractioninthenumericalsimulationofdynamicresponseofwarshipstructures,
basedontheGeers-
Huntermodel,amodifiedmodelforcalculatingtheunderwaterexplosionbubbleloadwasproposed
bycombiningwiththeboundaryelementmethod.Toovercometheshortcomingofthesecond-order
doubly-asymptoticapproximation(DAA2)methodintreatingthefluid-structureinteractionwithlow
frequencyandlargeamplitudemotion,anonlineardoubleasymptoticapproximation(NDAA)method
waspresentedbyconsideringthenonlinearfactorssuchastheviolentlow-frequencyresponseofthe
warshipanditsfreesurfaceeffect.AndacodewasdevelopedbycombiningthepresentedNDAA
methodwiththefiniteelementcodetonumericallyinvestigatethedynamicresponseofwarshipstructuressubjectedtounderwaterexplosionshock
avesandbubbles.Themeanerrorbetweennumerical
andexperimentalverticalvibrationvelocitiesatthedifferentpositionsisabout16.8%,anditdisplays
thatthepresentedNDAA methodisfeasible.
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