Two\|phase ,miscible,incompressible flow in porous media is governed by a system of nonlinear partial differential equations.Many numerical methods have been given by different authors to this system,but these methods...Two\|phase ,miscible,incompressible flow in porous media is governed by a system of nonlinear partial differential equations.Many numerical methods have been given by different authors to this system,but these methods need very high regularity conditions.Actually,in most practical applications these regularity conditions couldn't be satisfied.In this paper,the problem of discontinuous coefficients with lower regularity conditions is considered and the error estimates are demonstrated.展开更多
Using the method of undetermined function, a set of 12 parameter rectangular plate element with double set parameter and geometry symmetry is constructed. Their consistency error are O(h\+2) , one order higher than...Using the method of undetermined function, a set of 12 parameter rectangular plate element with double set parameter and geometry symmetry is constructed. Their consistency error are O(h\+2) , one order higher than the usual 12 parameter rectangular plate elements.展开更多
This paper studies the finite element method for some nonlinear hyperbolic partial differential equations with memory and dampling terms.A Crank\|Nicolson approximation for this kind of equations is presented.By using...This paper studies the finite element method for some nonlinear hyperbolic partial differential equations with memory and dampling terms.A Crank\|Nicolson approximation for this kind of equations is presented.By using the elliptic Ritz\|Volterra projection,the analysis of the error estimates for the finite element numerical solutions and the optimal H \+1\|norm error estimate are demonstrated.展开更多
The transientbehaviorofisotropic and hom ogeneousplateshasbeen a subjectofinterest. Thepresentinvestigation isconcerned w ith the largedeflection transientanalysisand controlofplates w ith piezoelectricsensorsand ac...The transientbehaviorofisotropic and hom ogeneousplateshasbeen a subjectofinterest. Thepresentinvestigation isconcerned w ith the largedeflection transientanalysisand controlofplates w ith piezoelectricsensorsand actuatorsunderapplied transverse loads. In this paper, the increm ental finite elem entequationsconsidering thegeom etricnonlinearity ofpiezoelectricsm artstructuresarede- veloped based on TotalLagrange approach by using the virtualvelocity increm entalvariationalprinci- ples. A four-node Mindlin plate elem ent w ith reduced and selective integration is adopted. The re- sulting increm entequationsare solved by using New m ark'sdirectintegration approach. Transientre- sponse ofplatesw ith piezoelectricsensorsand actuators subjected to transverse dynam ic loading isin- vestigated. The active dam ping isintroduced on the platesby coupling a negativevelocity feedback al- gorithm in a closed controlloop. The num ericalresults show thatpiezoelectric actuators can produce significant dam ping and suppress transient vibration effectively. Finally, the effects of the num ber and locations ofthe piezoelectric actuatorson the controlsystem are also investigated.展开更多
In this paper,a new numerical method,the coupling method of spherical harmonic function spectral and finite elements,for a unsteady transport equation is discussed,and the error analysis of this scheme is proved.
The mold filling of RTM was simulated based on the control volume finite element method (CV/FEM). The formulat ion using isoparametric transformation was discussed in detail and a computation al code based on isopara...The mold filling of RTM was simulated based on the control volume finite element method (CV/FEM). The formulat ion using isoparametric transformation was discussed in detail and a computation al code based on isoparametric technique was developed. The simulation results w ere compared with experimental data. Different isoparametric elements, quadrilat eral and triangular, were compared in the simulation.It demonstrates that the us e of bilinear quadrilateral isoparametric elements in simulating the process can produce a higher precision and cost a less time than the use of triangular ones .展开更多
文摘Two\|phase ,miscible,incompressible flow in porous media is governed by a system of nonlinear partial differential equations.Many numerical methods have been given by different authors to this system,but these methods need very high regularity conditions.Actually,in most practical applications these regularity conditions couldn't be satisfied.In this paper,the problem of discontinuous coefficients with lower regularity conditions is considered and the error estimates are demonstrated.
文摘Using the method of undetermined function, a set of 12 parameter rectangular plate element with double set parameter and geometry symmetry is constructed. Their consistency error are O(h\+2) , one order higher than the usual 12 parameter rectangular plate elements.
文摘This paper studies the finite element method for some nonlinear hyperbolic partial differential equations with memory and dampling terms.A Crank\|Nicolson approximation for this kind of equations is presented.By using the elliptic Ritz\|Volterra projection,the analysis of the error estimates for the finite element numerical solutions and the optimal H \+1\|norm error estimate are demonstrated.
文摘The transientbehaviorofisotropic and hom ogeneousplateshasbeen a subjectofinterest. Thepresentinvestigation isconcerned w ith the largedeflection transientanalysisand controlofplates w ith piezoelectricsensorsand actuatorsunderapplied transverse loads. In this paper, the increm ental finite elem entequationsconsidering thegeom etricnonlinearity ofpiezoelectricsm artstructuresarede- veloped based on TotalLagrange approach by using the virtualvelocity increm entalvariationalprinci- ples. A four-node Mindlin plate elem ent w ith reduced and selective integration is adopted. The re- sulting increm entequationsare solved by using New m ark'sdirectintegration approach. Transientre- sponse ofplatesw ith piezoelectricsensorsand actuators subjected to transverse dynam ic loading isin- vestigated. The active dam ping isintroduced on the platesby coupling a negativevelocity feedback al- gorithm in a closed controlloop. The num ericalresults show thatpiezoelectric actuators can produce significant dam ping and suppress transient vibration effectively. Finally, the effects of the num ber and locations ofthe piezoelectric actuatorson the controlsystem are also investigated.
文摘In this paper,a new numerical method,the coupling method of spherical harmonic function spectral and finite elements,for a unsteady transport equation is discussed,and the error analysis of this scheme is proved.
基金Funded by the National Natural Science Foundation of China ( 19872051 ) and the National "863" H tech Foundation(2001AA335020)
文摘The mold filling of RTM was simulated based on the control volume finite element method (CV/FEM). The formulat ion using isoparametric transformation was discussed in detail and a computation al code based on isoparametric technique was developed. The simulation results w ere compared with experimental data. Different isoparametric elements, quadrilat eral and triangular, were compared in the simulation.It demonstrates that the us e of bilinear quadrilateral isoparametric elements in simulating the process can produce a higher precision and cost a less time than the use of triangular ones .
