INITIAL BOUNDARY VALUE PROBLEMS FOR A CLASS OF NONLINEAR INTEGRO－PARTIAL DIFFERENTIAL EQUATIONS

ＩＮＩＴＩＡＬＢＯＵＮＤＡＲＹＶＡＬＵＥＰＲＯＢＬＥＭＳＦＯＲＡＣＬＡＳＳＯＦＮＯＮＬＩＮＥＡＲＩＮＴＥＧＲＯ－ＰＡＲＴＩＡＬＤＩＦＦＥＲＥＮＴＩＡＬＥＱＵＡＴＩＯＮＳＣｕｉＳｈａｎｇ－ｂｉｎ（崔尚斌）（Ｄｅｐｔ．ｏｆＭａｔｈ．,ＬａｎｚｈｏｕＵｎｉ...     

ANALYTICAL SOLUTION OF RADIATED SOUND PRESSURE OF RING－STIFFENED CYLINDRICAL SHELLS IN FLUID MEDIUM

ＡＮＡＬＹＴＩＣＡＬＳＯＬＵＴＩＯＮＯＦＲＡＤＩＡＴＥＤＳＯＵＮＤＰＲＥＳＳＵＲＥＯＦＲＩＮＧ－ＳＴＩＦＦＥＮＥＤＣＹＬＩＮＤＲＩＣＡＬＳＨＥＬＬＳＩＮＦＬＵＩＤＭＥＤＩＵＭＸｉｅＧｕａｎｍｏ（谢官员模）ＬｕｏＤｏｎｇｐｉｎｇ（骆东平）（Ｒｅｃｅｉｖ...     

A－HIGH－ORDER ACCURACY EXPLICIT DIFFERENCE SCHEME FOR SOLVING THE EQUATION OF TWO－DIMENSIONAL PARABOLIC TYPE

Ａ－ＨＩＧＨ－ＯＲＤＥＲＡＣＣＵＲＡＣＹＥＸＰＬＩＣＩＴＤＩＦＦＥＲＥＮＣＥＳＣＨＥＭＥＦＯＲＳＯＬＶＩＮＧＴＨＥＥＱＵＡＴＩＯＮＯＦＴＷＯ－ＤＩＭＥＮＳＩＯＮＡＬＰＡＲＡＢＯＬＩＣＴＹＰＥＭａＭｉｎｇｓｈｕ（马明书）（ＲｅｃｅｉｖｅｄＪｕｎｅ２,１...     

SPATIAL－TEMPORAL DISCRETE COORDINATION OF FEM AND DIRECT INTEGRAL METHOD FOR TRANSIENT DYNAMIC PROBLEMS

ＳＰＡＴＩＡＬ－ＴＥＭＰＯＲＡＬＤＩＳＣＲＥＴＥＣＯＯＲＤＩＮＡＴＩＯＮＯＦＦＥＭＡＮＤＤＩＲＥＣＴＩＮＴＥＧＲＡＬＭＥＴＨＯＤＦＯＲＴＲＡＮＳＩＥＮＴＤＹＮＡＭＩＣＰＲＯＢＬＥＭＳＷａｎｇＨｕａｉ－ｚｈｏｎｇ（王怀忠）（ＳｈａｎｇｈａｉＵｎｉｖｅｒ...     

FINITE ELEMENT ANALYSIS FOR THE UNSTEADY NEARSHORE CIRCULATION DUE TO WAVE－CURRENT INTERACTION（II）──TWO－STEP EXPLICIT FINITE ELEMENT METHOD

ＦＩＮＩＴＥＥＬＥＭＥＮＴＡＮＡＬＹＳＩＳＦＯＲＴＨＥＵＮＳＴＥＡＤＹＮＥＡＲＳＨＯＲＥＣＩＲＣＵＬＡＴＩＯＮＤＵＥＴＯＷＡＶＥ－ＣＵＲＲＥＮＴＩＮＴＥＲＡＣＴＩＯＮ（ＩＩ）──ＴＷＯ－ＳＴＥＰＥＸＰＬＩＣＩＴＦＩＮＩＴＥＥＬＥＭＥＮＴＭＥＴＨＯＤＷ...     

THREE DIMENSIONAL STRESS ANALYSIS OF SYMMETRIC COMPOSITE LAMINATES UNDER UNIAXIAL EXTENSION AND IN－PLANE PURE SHEAR

ＴＨＲＥＥＤＩＭＥＮＳＩＯＮＡＬＳＴＲＥＳＳＡＮＡＬＹＳＩＳＯＦＳＹＭＭＥＴＲＩＣＣＯＭＰＯＳＩＴＥＬＡＭＩＮＡＴＥＳＵＮＤＥＲＵＮＩＡＸＩＡＬＥＸＴＥＮＳＩＯＮＡＮＤＩＮ－ＰＬＡＮＥＰＵＲＥＳＨＥＡＲＣｈｉｃｎｗｅｉ－ｚａｎｇ（钱伟长）,Ｈｕａｎｇ...     

NUMERICAL SIMULATION OF FLOW OF HIGHLY VISCOELASTIC FLOW IN THREE－DIMENSIONAL VARYING THICK SLIT CHANNEL

（杨伯源）（李勇）ＮＵＭＥＲＩＣＡＬＳＩＭＵＬＡＴＩＯＮＯＦＦＬＯＷＯＦＨＩＧＨＬＹＶＩＳＣＯＥＬＡＳＴＩＣＦＬＯＷＩＮＴＨＲＥＥ－ＤＩＭＥＮＳＩＯＮＡＬＶＡＲＹＩＮＧＴＨＩＣＫＳＬＩＴＣＨＡＮＮＥＬ￥ＹａｎｇＢｏｙｕａｎ；ＬｉＹｏｎｇ（Ｄｅｐａｒｔ...     

A NON－INCREMENTAL TIME－SPACE ALGORITHM FOR NUMERICAL SIMULATION OF FORMING PROCESS

ＡＮＯＮ－ＩＮＣＲＥＭＥＮＴＡＬＴＩＭＥ－ＳＰＡＣＥＡＬＧＯＲＩＴＨＭＦＯＲＮＵＭＥＲＩＣＡＬＳＩＭＵＬＡＴＩＯＮＯＦＦＯＲＭＩＮＧＰＲＯＣＥＳＳＬｉｕＢａｏｓｈｅｎｇ（柳葆生）ＣｈｅｎＤａｐｅｎｇ（陈大鹏）ＬｉｕＹｕ（刘渝）（ＲｅｃｅｉｖｅｄＡｐｒ...     

RUDIMENTAL EQUATIONS FOR THERMO－ELASTO－PLASTIC STRESS ANALYSIS DURING CONTINUOUS CASTING WITH PHASE CHANGE

ＲＵＤＩＭＥＮＴＡＬＥＱＵＡＴＩＯＮＳＦＯＲＴＨＥＲＭＯ－ＥＬＡＳＴＯ－ＰＬＡＳＴＩＣＳＴＲＥＳＳＡＮＡＬＹＳＩＳＤＵＲＩＮＧＣＯＮＴＩＮＵＯＵＳＣＡＳＴＩＮＧＷＩＴＨＰＨＡＳＥＣＨＡＮＧＥＺｈａｏＸｉｎｇ－ｈｕａ（赵兴华）;ＣｈｅｎｇＸｉａｏ－ｄｉ...     

CONSTRUCTION OF MODIFIED TAYLOR－GALERKIN FINITE ELEMENTS AND ITS APPLICATION IN COMPRESSIBLE FLOW COMPUTATION

ＣＯＮＳＴＲＵＣＴＩＯＮＯＦＭＯＤＩＦＩＥＤＴＡＹＬＯＲ－ＧＡＬＥＲＫＩＮＦＩＮＩＴＥＥＬＥＭＥＮＴＳＡＮＤＩＴＳＡＰＰＬＩＣＡＴＩＯＮＩＮＣＯＭＰＲＥＳＳＩＢＬＥＦＬＯＷＣＯＭＰＵＴＡＴＩＯＮＣＯＮＳＴＲＵＣＴＩＯＮＯＦＭＯＤＩＦＩＥＤＴＡＹＬＯＲ...     

Finite element analysis for the unsteady nearshore circulation due to wave-current interaction (I)—numerical model

In this paper, a numerical model for predicting the unsteady nearshore circulation due to wave-current interaction was proposed. In addition to the traditional continuity, momentum and energy equations, the dispersion and refraction relations were included in the governing equations. Moreover, the effects of lateral shears, wind, radiation and bottom stresses were analysed in the governing equations. Therefore, we expect that this model may more completely and exactly reflect the law of wave-current interaction. In part (II) we will adopt the selective lumping two-step explicit finite element method to solve the model, and some examples will be presented.     

A note on probabilistic interpretation for quasilinear mixed boundary problems

I.Intr0ducti0nWekn0wthattheprobabilisticrepresentationofsolutionsofpartialdifferentia1equationswiththemixedboundaryconditi0nshasmanyimp0rtantapplicationsbothintheoryofpartialdifferentialequationsandinthat0fstochasticdifferentialequationswithreflectingboun…     

Postbuckling behavior of rectangular moderately thick plates and sandwich plates

ＰＯＳＴＢＵＣＫＬＩＮＧＢＥＨＡＶｉＯＲＯＦＲＥＣＴＡＮＧＵＬＡＲＭＯＤＥＲＡＴＥＬＹＴＨＩＣＫＰＬＡＴＥＳＡＮＤＳＡＮＤＷＩＣＨＰＬＡＴＥＳＣｈｅｎｇＺｈｅｎ－ｑｉａｎｇ（成振强）ＷａｎｇＸｉｕ－ｘｉ（王秀喜）ＨｕａｎｇＭａｏ－ｇｕａｎｇ（黄茂光）...     

Influence of water molecule diffusion resistance force on electro-actuating characteristics of ionic polymer-metal

基于Tadokoro理论模型,采用有限元方法对离子交换膜金属复合材料 (ionic polymer metal composite, IPMC)的电致动特性进行了数值模拟. 通过比较求解控制方程中不考虑水分子扩散阻力和考虑水分子扩散力的两种计算模型, 着重探讨和比较了水分子扩散阻力对钠离子携带周围水分子的迁移运动规律和变形过程中各 个特征物理量的影响. 结果表明,控制方程中增加水分子扩散阻力这一非线性项,对最终的 宏观挠曲位移影响并不明显;但是对于钠离子浓度、等效应变、内部平衡力分布等物理量影 响很大;这种影响还具有区域性特征,主要集中于电极板附近区域,其他区域影响较弱. 控 制方程中增加水分子扩散力可以更准确地描述钠离子在迁移过程各物理量的变化规律.     

Shock conditions for hypoelastic materials

The equations governing the motion of hypoelastic materials (and related models of non-Newtonian fluids) are not in conservation form. Hence there is no obvious formulation of Rankine-Hugoniot jump conditions across a shock. In this paper we demonstrate that a viscosity criterion can be used to obtain meaningful shock conditions. In particular, we discuss shocks of small amplitude. The shock conditions obtained will in general depend on the form of the viscosity term.Michael Renardy's research was supported by the National Science Foundation under Grant DMS-9008497.     

Exact dynamic solutions to piezoelectric smart beams including peel stresses I: Theory and application

This work presents exact dynamic solutions to piezoelectric (PZT) smart beams including peel stresses. The governing equations of partial differential forms are firstly derived for a PZT smart beam made of the identical adherends, and then general solutions of the governing equations are studied. The analytical solutions are applied to a cantilever beam with a partially bonded PZT patch to the fixed end. For the given boundary conditions, exact solutions of the steady state motions are obtained. Based on the exact solutions, frequency spectra, natural frequencies, normal mode shapes, harmonic responses of the shear and peel stresses are discussed for the PZT actuator. The details of the numerical results and sensing electric charges will be presented in Part II of this work. The exact dynamic solutions can be directly applied to a PZT bimorph bender. To compare with the classic shear lag model whose numerical demonstrations will be given in Part II, the related equations are also derived for the shear lag rod model and shear lag beam model.     

Numerical analysis of an asymptotic model for the collapse of a vapor bubble

In this work, we analyze the thermal collapse of a vapor bubble immersed in a unbounded and subcooled liquid. In this thermal regime, controlled basically by Jakob number (Ja), we present an asymptotic limit of the governing equations by identifying the appropriate temporary and spatial scales to solve numerically the mathematical model. In the limit of Ja ≫ 1, the governing equations describe the spatial and temporal evolution of the adjacent thermal boundary layer to the radius of the bubble. In particular, we prove that the influence of curvature effects due to conductive and convective heat terms of the energy equation for the liquid are responsible to characterize the thermal collapse regime. The numerical results for the evolution of the nondimensional radius of the bubble, a, and the corresponding nondimensional temperature profiles, θ, for different values of the Ja, show that the ending collapse state has a singular behavior, which we have denoted as a “thermal runaway”.     

Two-dimensional generalized thermoelasticity problem for a half-space subjected to ramp-type heating

In this paper, we will consider a half-space filled with an elastic material, which has constant elastic parameters. The governing equations are taken in a unified system from which the field equations for coupled thermoelasticity as well as for generalized thermoelasticity can be easily obtained as particular cases. A linear temperature ramping function is used to more realistically model thermal loading of the half-space surface. The medium is assumed initially quiescent. Laplace and Fourier transform techniques are used to obtain the general solution for any set of boundary conditions. The general solution obtained is applied to a specific problem of a half-space subjected to ramp-type heating. The inverse Fourier transforms are obtained analytically while the inverse Laplace transforms are computed numerically using a method based on Fourier expansion techniques. Some comparisons have been shown in figures to estimate the effect of the ramping parameter of heating with different theories of thermoelasticity.     

An improved large eddy simulation of two-phase flows in a pump impeller

An improved large eddy simulation using a dynamic second-order sub-grid-scale (SGS) stress model has been developed to model the governing equations of dense turbulent particle-liquid two-phase flows in a rotating coordinate system, and continuity is conserved by a mass-weighted method to solve the filtered governing equations. In the current second-order SGS model, the SGS stress is a function of both the resolved strain-rate and rotation-rate tensors, and the model parameters are obtained from the dimensional consistency and the invariants of the strain-rate and the rotation-rate tensors. In the numerical calculation, the finite volume method is used to discretize the governing equations with a staggered grid system. The SIMPLEC algorithm is applied for the solution of the discretized governing equations. Body-fitted coordinates are used to simulate the two-phase flows in complex geometries. Finally the second-order dynamic SGS model is successfully applied to simulate the dense turbulent particle-liquid two-phase flows in a centrifugal impeller. The predicted pressure and velocity distributions are in good agreement with experimental results. The project supported by the National Natural Science Foundation of China (50779069 and 90510007), the Start-up Scientific Research Foundation of China Agricultural University (2006021) and the Beijing Natural Science Foundation (3071002).     

非牛顿流体经波纹管流动的阻力特性

本文对Carreau流体经波纹管的蠕动流的阻力特性用差分方法作了数值求解。先施行坐标变换,提出一种保证周期性条件的混合迭代法,能较快得到问题的收敛解。流体的物质参数以及流动区域的几何参数对流动阻力特性的影响作了讨论,同时指出了直径均匀的毛管模型作为渗流模型的不足之处。