冲击渐进振动系统相邻基本振动的转迁规律

冲击振动现象广泛存在于动力机械系统中,使得系统表现出复杂的动力学响应.目前对冲击振动系统的p/1类基本振动的稳定性及分岔研究报道较少,而且已有的对冲击振动系统动力学的研究基本都是基于单参数分岔进行分析的.研究以小型振动冲击式打桩机为工程背景,建立了冲击渐进振动系统的力学模型.分析了激振器和缓冲垫发生碰撞的类型,以及滑块渐进运动的条件.给出了系统可能呈现的四种运动状态的判断条件和运动微分方程.通过二维参数分岔分析得到系统在(ω,l)参数平面内存在的各类周期振动的参数域和分布规律.详细分析了相邻p/1类基本振动的转迁规律.在5/1基本振动的参数域的右边区域,相邻p/1基本振动的参数域临界线上存在一个奇异点X_p,相邻p/1类基本振动的分岔特点以奇异点X_p为临界点.在l小于l_X_p的区域内,相邻p/1基本振动经实擦边分岔和鞍结分岔相互转迁,实擦边分岔线和鞍结分岔线之间存在迟滞域,迟滞域内,系统存在两个周期吸引子共存的现象.在l大于l_X_p的区域内,相邻p/l类基本振动的参数域之间存在一个中间过渡区域.中间过渡区域内,系统呈现(2p+2)/2和(2p+1)/2周期振动等.在5/1基本振动的参数域的左边区域,p/1基本振动经多重滑移分岔产生(P+1)/1基本振动.     

Analysis of energy release rate for cracked laminates

1.IntroductionFailurebehaviorofcompositematerialsandsomeothermaterialslikewoodsandorientedpolymersaregovernedbyanisotropicandheterogeneouscharacteristics(Suoetal.,l99l,O'Brien,l987)I"21.ltiswell-knownthattheelasticstressfieldatthecracktiphasaninversesquarerootsingularityforgenerallyanisotropicbuthomogeneousmaterials(Hoenig,1982)l,l.ForheterogeneousmatCrials,aslongastheelasticmoduliarecontinuousanddifferentiablefunctionsofthespatialcoordinates,thisinversesquarerootsingularitystillprevails(Eis…     

ON THE SOLUTION OF NONLINEARTWOPOINT BOUNDARY VALUE PROBLEM──u" g(t.u) = f(t),u(0) = u(2π) = 0

I.IntroductionLetHbearealHilbertspace,XandYtwoclosedsubspacesofHsuchthatH=X$Y,T:H-HaC'mapping,n>1.Assumethatthereexisttwopositiveconstantsniland)liZsuchthatforVueH,Vx6X,VYey'Undertheconditions(l.1),(l.2)and(l.3),ManasevichprovedthatTisaC"diffeomorphismontoH'tl].ThepurposeofthispaperistoimprovetheaboveManasevich'shomeomQrphismtheorem,andthen,itisusedtoproveanexistenceanduniquenessresultforthenonlineartulopointboundaryvalueproblem11.ANonVariationalVersionofaMax-MinPrincipleToimprov…     

Singular perturbation for a class of coupled chemical reaction and diffusion systems

I.IntroductionTherearemanyresu1tsaboutsingularperturbationfore1lipticandparabolicequations(orsystem)l"2l.AsfOrsingularlyperturbedreactionanddiffusionsystem,moststudiesareobtuinedundertheassumptionofnocoupledterm13].However,thecoupledsystemsusua1lyoccurredinapplicationssuchassimplefoodchainwithdiffusionandgroupdefencesystem(!landchemicalreactiondiffusionsysteml'landsoon.It'smorecomplicatedtodealwithsuchproblems.Andmoreover,thesolutionofthesameproblemmaypossessdifferentbchaviorsaccordingtothep…     

Fourth-order accurate difference method for the singular perturbation problem

I.IntroductionForaclassofhoundaryvalueproblemsofdifferentia1equation,whichiswidelyappIiedinmechanicswhereeC(O,eo),e,<<1,isasmalIperturbationparameter-andf(x),a(x)satisfytheNumericaltreatmentofproblem(l.l)wasgivenin[lO].[l2].In[lO].auniform1yconvergentdiff…     

关于在活荷激发的振动中能量来源的讨论

.问题的提出一个竖向轮压活荷P以水平速度v从如图1所示的梁上通过,若进口和出口处有相同的高程,则当竖向轮压活荷走完梁的全跨度l时,重轮的位置最终又回到了它原来出发时的高程上,它所做的功应当等于零,即 ...     

The globalization of Durand-Kerner algorithm

I.Intr0ductionForflndingallzerosofacomplexpolynomialofdegree;Ip(z)=zu olz'-l ..' a.-1z a.(l.l)whenzerosareal1simple,manymethodsareavailable.AmongthemaretheDurand-Kerneralgorithm,theAberthalgorithm,thesquarerootingaIg0rithmandtheirvarietiesI3'[1'141.Thecom…     

Algorithm of solutions for mixed-nonlinear variational-like inequalities in reflexive banach space

I.IntroductionLetDbeanonemptyconvexsubsetofaBanachspaceB,BbethetopologicaldualspaceofBand(u,v)bethepairingbetweenneBandr6B.LetT,A:D~B'and9:DxD-Bbethreemappingsandf:D~(-ac, ac1beareal-valuedfunction.Inthispaper,weshallinvestigatethemixednonlinearvariationalinequalityproblemMNna(T,A,9,f,D):FinduEDsuchthatSpecialCases.(l)f-0,thentheproblem(l.l)isequivalenttofindingueDsuchthatTheproblem(l.2)isthestronglynonlinearvariational-likeinequalityproblemstudiedbyNoorllJwhicharisesnaturallyincon…     

Boundary value problem for a singularly perturbed nonlinear system

I.Intr0ducti0n'Manyresultshavebeeng0tinstudyingthesingu1arperturbation0fboundaryvalueproblemfornonlinearsystemeg#=j(t,g,y',8)(l.l)bythemethodandthetechniqueofdiagonalizationl'~'l.Thepapersarebasedonsucha.conditionthattheeigenvaluesofJacobimatrixlu'offwit…     

An analytical solution and analysis of characters for viscoelastic fluid flow in annular pipe

I.Introducti0nLuiCiqunandHuangJunqiI'I(l989),ZhuWeihuiandLuiCiquri1'l(l992)sequentiallystudiedtheaxialflowofsecondorderandMaxwellfluidsandanalyzedtheflowcharactersofthesefluids.Thispaperwillstudyunsteadyrotat0ryflowofsecondorderandMaxwellfluidsinannularpi…