Abstract: In this paper by means of the exact analytic method ,the general solution for dynamic response of nonhomogeneous beam with variable cross section is obtained under arbitrary resonant load and boundary conditions.The problem is reduced to solvea non-positive differential equation.Generally,it is not solved by variational method.By the present method,the general solution for this problem may be written as an ana-lytic form.Hence,it is convenient for structure optimizing problem.In this paper,its convergence is proved.Numerical examples are given at the end of the paper.which in-dicates satisfactory results can be obtained.
Abstract: Based on fundamental assumptions,an analysis of the constitutive relations be-tween the internal.forces and deformations of discrete rectangular recirculated struturesis given.On the basis of this,an equivalent continuum model is adopted and the ap-plication of the principle of virtual work leads to non-linear governing equations and corresponding boundary conditions.
Abstract: Using Stricklin Melhod,we have this paper has derived the formulas for the ge-neration of non-linear element stiffness matrix of a triangle element when considering both the bending and the in-plane membrane forces.A computer programme for the calculation of large deflection and inner forces of shallow shells is designed on theseformulas.The central deflection curve computed by this programme is compared with other pertaining results.
Abstract: Numerical simulation for evolutionary history of an oil-and gas-bearing basin is to repeat geological and thermodyanomic history of basin evolution on a computer and then to quantitatc petroleum generation,accumulation and migration.The mathemat-ical model describing geological and thermodynamic history of the basin evolution ischaracterised by an initial-boundary value problem of a system of nonlinear partial dif-ferential equations.In the present paper,a numerical method for three-dimensional problem and the analysis of its stability are established and a numerical result for apractical model is given,which shows that the abnormal pressure and paleo-temperat-ure computed are reasonable and display physical characteristics clearly as well.
Abstract: The equations describing the flow of a viscoplastic fluid on a rotating disk are de-rived and are solved by perturbation technique and nurmerical computation respectively for 2 cases.This makes it possible to calculate the thickness distribution of film.Twokinds of distribution of thickness have been found.For the viscoplastic fluid for whichboth viscosity and yield stress are independent of radial coordinate r,the thickness h decreases with increasing r.For a Bingham fluid for which both viscosity and yieldstress are function of time and r.the thickness h increases with increasing r.
Abstract: In this paper,fundamental equations of the axisymmetric large amplitude.free vibration for circular sandwich plates are derived by means of Hamilion principle.Inmosi cases,the sandwich plates are composed of very thin faces,then the preceding fundamental equations are simplified considerably.For an illusirative example,a circu-lar sandwich plate with edge clamped but free to slip is considered,and then we gol a pure analytic solution of the axisvmmetric large amplitude free vibration with the aid of the modified iteration method.and derived an analytic relation for the amplitude-frequency response.
Abstract: In this paper,(a)we rerise Theorem 2 of Ref  omit the condition V7>07>0.(b)we discuss the relative positions of six curvesM(s2,r)=0,J(s2,r)=0,L(s2,r)=0,T(s2,r)=0,s2=s> and s2=s Under the condition of the(1.3)distri-butions of limit cycles,we expand the variable regions of parameters(s,r)and clearly.show them in figure,(c)we study the(1,3)distributions of limit cycles of one kind quadratic systems with two singular points at the infinite: and(d)we give a generalmethod to discuss the(1,3)distibutions`of limit cycles of system(1.1)whatever there isone,two or three singular points at the infinite.
Abstract: In this paper a linearized and unified yield crierion of metals is presented,which is in a form of a set of linear functions with two pararneters.The parameters are expressed in terms of tension yield stress and so-called "shear-stretch ratio" and can bereadily determined from experimental data.It is shown that in stress space the set of yield functions is a set of polygons with twelve edges located between the Tresca's hexagon and twin-shear-stress hexagon.In this paper the present yield function isused to analyse the prestressiap loose running fit cylinders.
Abstract: The generalized KdV equation ut+αuux+μux3+εux5=0 is a typical integr-able equation.It is derived studying the dissemination of magnet sound wave in coldplasma,Ihe isolated wave in transmission line,and the isolated wave in the bound-ary surface of the divided layer fluid.For the characteristic problem of the gene-ralized KdV equation,this paper,based on the Riemann function,designs a suitable structure,then changes the characteristic problem to an equivalent integral and dif-ferential equation whose corresponding mapping E is a mapping to itself.According to the principle of fixed point,the above integral differential equ-ation has a unique regular solution,so the characteristic problem of the generalized KdV equation has a.unique solution.The iteration solution derived from the integral differential equation sequence is uniformly convegent in Ω .
Abstract: The crack-tip field under plane stress condition for an incompressible rubber material is investigated by.the use of the fully nonlinear equilibrium theory.It is found thai the crack-tip field is composed of two shrink sectors and one expansion se-ctor.At the crack-tip,stress and strain possess the singularity of R-1 and R-1n,respec-tively,(R is the distance to the crack-tip before deformation,n is the material const-ant).When the crack-tip is approached,the thickness of the sheet shrinks to zerowith the order of R1.4n.The results obtained in this paper are consistent with that ob-tained in  when s→χ.