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DIES OF BURGERS EQUATION USING A LATTICE BOLTZMANN METHOD

1999, 31(2) doi: 10.6052/0459-1879-1999-2-1995-016

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GAS TRANSFER BY BUBBLES BETWEEN OCEAN AND ATMOSPHERE

The gas transfer by small bubbles in waves in the ideal fluid is studied in this paper.The motion equation coupled with the gas transfer result for the homogeneous flow over a sphericalbubble is solved. The effects of the gas concentration dissolved in the water, waves, the bubbleradius and the initial depth of bubbles on the gas diffusion of a single bubble are discussed. Therelationship between the gas diffusion from a bubble and the gas concentration in water is basicllylinear. The wave lenth has no effe...

1999, 31(2): 129-136. doi: 10.6052/0459-1879-1999-2-1995-014

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THE LIQUID BRIDGE WITH MARANGONI EFFECT

The Bio-harmonic Function is selected as the Level-function used in the Level-Setmethod. The new defined Level-function overcomes the defects of the Level-function defined byOsher. The internal flow of the liquid bridge with Marangoni's effect taken into consideration isstudied. Besides giving the real free surface, it also proves that the big secondary vortex pairgotten by Zhang doesn't exist.

1999, 31(2): 137-142. doi: 10.6052/0459-1879-1999-2-1995-015

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NEW SPACE-TIME CONSERVATION SCHEMES FOR SOLVING 2-D EULER EQUATIONS

The method of space-time conservation element and solution element (the CE/SEmethod, for short), developed by S.C. Chang[1], is a new numerical method which differs fromthe well-established methods and has many noniraditional features. Firstly, space and time areunified and treated on the same footing, and by the introduction of conservation element andsolution element, both local and global flux conservations in space and time instead of in spaceonly are enforced. Secondly, a zigzagging marching strategy i...

1999, 31(2): 152-158. doi: 10.6052/0459-1879-1999-2-1995-017

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EVOLUTION OF WAVE-PACKET IN THREE-DIMENSIONAL BOUNDARY LAYER ON A SWEPT WING

The evolution character of a isolated wave-packet produced by a point source in threedimensional boundary layer on a swept flat plate is investigated. From numerical solution of lineareigenvalue problem of spatial mode, the amplitude and phase of wave-packet at each position onthe growing path is obtained from the integral over all spanwise wavenumbers of colltribution toit's amplitude. The steepest descent method is also used to evaluate it's asymptotic behavior. Itis demonstrated that the streaks observed...

1999, 31(2): 159-164. doi: 10.6052/0459-1879-1999-2-1995-018

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A FAMILY OF UNIFIED CLASSICAL VARIATIONAL PRINCIPLES IN COUPLED THERMOELASTO DYNAMICS

The variational principle (VP) of classical type (excluding the Blot's VP, the Gurtin'sVP, the least square VP & various constrained VP, in which some unknown variables are frozenduring the variation operation) for the entitled problem is extremely difficult to establish, so that upto now all VP for this problem, to more or less degree, are constrained VP with the only exception ofthe Grutin's VP. However, the Gurtin's VP posesses the following two essential short-comings: 1) itis confined only to linear di...

1999, 31(2): 165-172. doi: 10.6052/0459-1879-1999-2-1995-019

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NEW SOLUTION SYSTEM FOR PLATE BENDING AND ITS APPLICatION

The governing equation for plate bending is biharmonic equation, the traditionalsolution methodology is the semi-inverse one that causes limitations. The Airy stress function isusually applied traditionally for plane elasticity problems, it also satisfies biharmonic equation.The analogy between plate bending and plane elasticity problems had been noticed long before,but their solution systems are different each other, and the analogy relationship had not been usedsystematically. In this paper, the analogy i...

1999, 31(2): 173-184. doi: 10.6052/0459-1879-1999-2-1995-020

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A STUDY ON THE ELASTO-PLASTIC MECHANICAL BEHAVIOR OF TWO PHASE MEDIA UNDER NONPROPORTIONAL LOADING

Under the assumption that the yielding phenomenon is not effected by the meanstress, the strain history of a material can be described by a spatial curve (strain trace) in fivedimensional deviatoric strain space. Stresses are functions of the strain trace. We assume thatthe ideal homogeneous matrix obeys the Mises yielding criterion and isotropic hardening. Butwhen the second particles exist, the stress concentration will occur around the second particlesand the residual stresses occur under unloading. When...

1999, 31(2): 185-192. doi: 10.6052/0459-1879-1999-2-1995-021

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THEORETICAL ANALYSIS ON THE NON-LINEAR ELASTIC PROPERTIES OF THE AORTIC ARCH WALL

The study on the non-linear elajstic properties of the arterial wall is a precondition forstudying of the fluid properties and the propagation of pulsatile wave in blood vessels. In studiesof blood vessels, there were a lot of researches on the constitution of the straight blood vessels.But, there is not a theoretical model for analyzing the non-linear elastic properties of the curvedblood vessels, like aortic arch. In this paper j based on the study of the constitution of straightblood vessels, we proposed...

1999, 31(2): 193-203. doi: 10.6052/0459-1879-1999-2-1995-027

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A GEOMETRICAL MODEL FOR FINITE ELASTIC-PLASTIC DEFORMATION

in this paper, based on theory of internal state variables in continuum mechanics,a fibre bundle model of material states are presented. First of all, the states of material aredivided into the internal microstructural states and the external deformation states. Assumingthat the plastic deformation of material can be given by the internal states of material and theirevolution laws, a principal fibre bundle structure and the correspondent relationships between thegeometrical characterization and the mechanic...

1999, 31(2): 204-212. doi: 10.6052/0459-1879-1999-2-1995-028

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THE VIBRATION CONTROL OF LARGE FLEXIBLE STRUCTURE BY EIGENSTRUCTURE ASSIGNMENT METHOD

The eigenstructure assignment for large flexible structure is studied in the paper basedon the fact that vibration control of large flexible structure has the characteristics of possessingmuch more degrees of freedom at nodes, being not appropriate to directly measure the globalstructure parameters, taking too much computation time for its feedback and having need to redesigning the global controller if a component is partially modified. In order to reduce the amount ofcalculation, to facilitate modificatio...

1999, 31(2): 213-221. doi: 10.6052/0459-1879-1999-2-1995-029

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THE QUASI-FIXED-POINT TRACING METHOD FOR MULIT-PERIODIC-SOLUTIONS OF A NONLINEAR DYNAMIC SYSTEM

The Multi-Periodic-Solutions of a nonlinear dynamic system means that there existseveral periodic solutions in state space at the same time, it is determined by the nature of thenonlinear dynamic system and is an important characteristics of the nonlinear dynamic systemdiffering from the linear systems. Today the research of linear system is mature, but that of nonlinear system is very difficult. The problem of Multi-Periodic-Solutions of the nonlinear dynamicsystem is a very important and very complex prob...

1999, 31(2): 222-229. doi: 10.6052/0459-1879-1999-2-1995-022

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EXPERIMENTAL STUDY ON PERMEABILITY AND SETTLEMENT OF SATURATED SAND UNDER IMPACT LOADING

An experimental study on the deformation and filtration of saturated sands underimpact loading is carried out by examining the behavior of a saturated sand column dropping tothe ground. The longitudinal drainage pathways and horizontal cracks in the skeleton of saturatedsands are discovered. By means of analyzing the images, the phenomena (Occurring in sand sampleNo.1) can be summarized as follows: (1) Some horizontal cracks cross the full sections, generally, thenumber of these cracks is three. Some small ...

1999, 31(2): 230-237. doi: 10.6052/0459-1879-1999-2-1995-023

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AN ANALYTIC SOLUTION FOR POST-BUCKLING OF TUBULARS SUBJECTED TO AXIAL AND TORSIONAL LOADING IN HORIZONTAL CIRCULAR CYLINDERS

Buckling of radially confined oil tubulars is of significant importance to the oil industry.It will affect the life of the tubulars and cause difficulties in drilling and in oil production. Anumber of theoretical models have been developed to study the buckling load and the post-bucklingconfiguration of the tubular, but the most of the past studies have not considered the torsionalloads. Only recently, some investigators based on energy principle have derived some results forbelieal buckling of tubulars sub...

1999, 31(2): 238-242. doi: 10.6052/0459-1879-1999-2-1995-024

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DYNAMICS OF THIN ELASTIC PLATES IN LARGE OVERALL MOTIONS CONSIDERING GEOMETRIC NON-LINEARITY AND COUPLING DEFORMATION

The dynamical equations of thin elastic plates in large overall motions considering theeffects of geometric non-linearity and coupling deformation are obtained in this paper, and whicheffects to the dynamics of this system are analyzed. The plots of phase plane and time historyin case of considering geometric non-linearity and coupling deformation and only considering geometric non-linearity are shown in Fig.2 and Fig.3 respectively, and the plot of displacement oftransverse vibration is shown in Fig.4. The...

1999, 31(2): 243-249. doi: 10.6052/0459-1879-1999-2-1995-025

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STUDY ON SURFACE CONTACT STRESS DISTRIBUTION PROPERTIES FOR MULTI-LAYERED FOUNDATION DURING DYNAMIC CONSOLIDATION

in this paper, the solutions of surface contact stress distribution for multi-layeredfoundation in transform domain are presented by combining the hammer rigid kinetic equationand transform matrix method of three-dimensional axisymmetric elastodynamic problem for multilayered foundation during dynamic consolidation. The contact stress-time and settlement-timerelations are obtained, in which the Laplace-Hankel mixed inversion transforms are employed. Thecontact time is also determined. Moreover, the reliabil...

1999, 31(2): 250-250. doi: 10.6052/0459-1879-1999-2-1995-026

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