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时间:2018-07-23
《船桥碰撞过程引发的冲击动力学论题》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、Impactdynamicstopicsmotivatedbyship-bridgecollisionprocess船桥碰撞过程引发的冲击动力学论题王礼立1,陈国虞2,杨黎明1(1.宁波大学机械工程和力学学院,浙江宁波315211;2.上海海洋钢结构研究所,上海201204)摘要:对船桥撞击过程引发的几个冲击动力学论题进行了分析。研究表明:①为降低船撞力,应采用柔性(低的结构动态广义波阻抗)防撞装置;②撞击力所做的功,通过应力波传播转化为内能(变形能)与动能之和;而变形能中的不可逆部分愈高,防撞装置发挥的整体作
2、用愈大,则愈有利于防撞装置发挥缓冲耗能作用。并且如何让船舶尽早结束撞击并带走尽量多的剩余动能,应是防撞装置设计的关键点;③黏性耗能可缓冲撞击过程、延长撞击历时,有利于防撞装置发挥整体作用,进而为船舶在低应力下转向滑离、从而带走尽可能多的剩余动能创造条件。因此,船撞桥防护装置的设计应该建立在如下的科学设计理念上:ⅰ低波阻抗意义上的冲击柔性,ⅱ缓冲撞击过程意义上的粘性耗能,ⅲ防撞装置能及早发挥整体作用,化撞击集中力为分布载荷,以及ⅳ让船尽早滑离而带走尽量多的剩余动能。以钢丝绳防撞圈为主要元件的柔性耗能防撞装置是这一
3、防撞理念的工程应用实例,其有效性已为工程实践和实船撞击试验证实。关键词:船桥碰撞;冲击动力学;冲击力;能量转换;动态响应中图分类号:文献标志码:DOI:10.13465/j.cnki.jvs.2015.03.003U442AWANGLi-li1,CHENGuo-yu2,YANGLi-ming1(1.CollegeofMechanicalEngineeringandMechanics,NingboUniversity,Ningbo315211,China;2.ShanghaiMarineSteelStructur
4、eResearchInstitute,Shanghai201204,China)Abstract:Someimpactdynamicstopicsmotivatedbyship-bridgecollisionprocesseswereanalyzedhere.Itwasshownthat(1)inordertoreducetheimpactforce,aflexiblecrashworthydevicewithalowstructuraldynamicgeneralizedwaveimpedanceshould
5、beapplied;(2)theworkdonebytheimpactforceisconvertedviawavepropagationintotheinternalenergy(deformationenergy)andkineticenergy;thelargertheirreversiblepartoftheformer,thegreatertheoverallroleplayedbythecrashworthydevice,thebetterthebufferroleplayedbythecrashw
6、orthydevice;moreover,howtomaketheshipassoonaspossibleendthecollisionandcarryawayasmuchaspossibletheremainingkineticenergyshouldbeakeypoint;(3)viscousdissipationofenergycanbufferthecollisionprocess,prolongthedissipationduration,helpthecrashworthydevicetoplaya
7、noverallrole,andcreateaconditionforshiptoendthecollision;thus,thescientificdesignideaofacrashworthydeviceshouldbebasedon(i)impactflexibilitywithalowstructuralwaveimpedance,(ii)viscousdissipationofenergytobuffercollisionprocess,(iii)thecrashworthydevicetoplay
8、anintegralroleassoonaspossibletochangetheconcentratedimpactforceintoweakerdistributedloads,and(iv)tomaketheshipturnawayassoonaspossibleandtakeawaytheremainingkineticenergyasmuchaspossible.Asanen
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