Cold roll forming is a complicated metal processing, and its is very difficult to simulate the forming process. Based on the Updated-Lagrange method in the deformation mechanics, an elastic-plastic large deformation s...Cold roll forming is a complicated metal processing, and its is very difficult to simulate the forming process. Based on the Updated-Lagrange method in the deformation mechanics, an elastic-plastic large deformation spline finite strip method is developed to analyze cold roll forming of a thin channel section. The longitudinal membrane strain values on the edge of the deformed strip for four one-pass sequences in different fold angles are got. Simulated results are compared with the results from previously conducted experiments. The deviation of the simulated peak strain values is within 30% compared with the experimental results.展开更多
Partially filled pipeflows were encountered in drainage systems belonging to a family of unsteady flow problems. Basic equations were developed and numerically solved also by the characteristic different methods with ...Partially filled pipeflows were encountered in drainage systems belonging to a family of unsteady flow problems. Basic equations were developed and numerically solved also by the characteristic different methods with time-line interpolation scheme. The boundary conditions for the inflow, outflow, moving hydraulic jump and junctions were developed experimentally and numerically. Full scale model experiments were carried out. It is consequently clarified that numerical model is capable of predicting flow characteristics in realistic drainage networks.展开更多
The mathematical model of conical involute gears is developed based on the theory of gearing and the generating mechanism. Tooth contact analysis （TCA） is performed to examine the meshing and bearing contact of the ...The mathematical model of conical involute gears is developed based on the theory of gearing and the generating mechanism. Tooth contact analysis （TCA） is performed to examine the meshing and bearing contact of the conical involute gear pairs with intersected and crossed axes. In addition, the principal directions and curvatures of the gear surfaces are investigated and the contact ellipses of the mating tooth surfaces are also studied. Finally, the numerical illustrative examples are provided to demonstrate the computational results, test gears are made for tooth-bearing tests, and the conclusion is verified that the theory has the applicability.展开更多
This paper presents a new finite element method for solving static and dynamic problems in laying operation of pipelines. The effect of the viscoelastic soil behavior is considered by using the Pasternak foundation mo...This paper presents a new finite element method for solving static and dynamic problems in laying operation of pipelines. The effect of the viscoelastic soil behavior is considered by using the Pasternak foundation model. Some examples are also presented.展开更多
OBJECTIVE: The characteristics of lip-mouth region including the soft and hard tissues in smiling position with frontal fixed position photographic computer-aided analysis were studied. METHODS: The subjects were 80 p...OBJECTIVE: The characteristics of lip-mouth region including the soft and hard tissues in smiling position with frontal fixed position photographic computer-aided analysis were studied. METHODS: The subjects were 80 persons (40 male and 40 females, age range: 17 to approximately 25 years) with acceptable faces and individual normal occlusions. The subjects were asked to take maximum smiling position to accept photographic measurement with computer-aided analysis. RESULTS: The maximum smile line could be divided into 3 categories: low smile line (16.25%), average smile line (68.75%), and high smile line (15%). CONCLUSION: The method adopting maximum smiling position to study the lip-month region is reproducible and comparable. This study would be helpful to provide a quantitative reference for clinical investigation, diagnosis, treatment and efficacy appraisal.展开更多
In this paper the modern electron optical equipment is used to translate the clear image of speed moving bubbles in bubbling liquid on a sieve tray into the digital information stored in computer, and the computer aid...In this paper the modern electron optical equipment is used to translate the clear image of speed moving bubbles in bubbling liquid on a sieve tray into the digital information stored in computer, and the computer aided image processing technique is utilized to measure the bubble size distributions and interfacial areas under various operating conditions. And the dynamic behavior of bubbles in turbulent liquid is analyzed theoretically; the mechanism of bubble deformation and breakage is explored on the basis of Kolmogoroff′s isotropic turbulence hypothesis; the mathematical model for predicting the gas liquid interfacial area is proposed. The comparison between the simulated results and the experimental data shows that the model is higher in accuracy, simple in form and convenient in use.展开更多
In this paper a mathematical model of AIDS is investigated.The conditions of the existence of equilibria and local stability of equilibria are given.The existences of transcritical bifurcation and Hopf bifurcation are...In this paper a mathematical model of AIDS is investigated.The conditions of the existence of equilibria and local stability of equilibria are given.The existences of transcritical bifurcation and Hopf bifurcation are also considered.in particular,the conditions for the existence of Hopf bifurcation can be given in terms of the coefficients of the characteristic equation.The method extends the application of the Hopf bifurcation theorem to higher differential equations which occur in biological models,chemical models,and epidemiological models etc.展开更多
In the present paper an unsteady flow of polymer fluid, i.e. non-Newtonian fluid is studied. The constitutive equation of upper-convected Maxwell fluid is used. The variational approach due to Kantorovich is used for ...In the present paper an unsteady flow of polymer fluid, i.e. non-Newtonian fluid is studied. The constitutive equation of upper-convected Maxwell fluid is used. The variational approach due to Kantorovich is used for the unsteady problem of the fluid. A special computer program `MACSYMA' is used to get the different approximation of the method of Kantorovich. The present method developed is called Computational Analytical Method which is available for the scientific research.展开更多
With the help of the decline method, a computer-aided analysis program of Christofell equation is described which makes it possible to calculate elastic and viscous constants of crystals precisely and easily. The elas...With the help of the decline method, a computer-aided analysis program of Christofell equation is described which makes it possible to calculate elastic and viscous constants of crystals precisely and easily. The elastic constants of LiNbO3 and Bi12 GeO20 crystals are calculated with an Apple - II computer and the Fortran program suggested; the calculated data are compared with the values achieved by others.展开更多
An eight-node solid-beam element based on absolute nodal coordinate formulation(ANCF)which uses cubic interpolation at the longitudinal direction and linear at the transverse direction is proposed.The element can accu...An eight-node solid-beam element based on absolute nodal coordinate formulation(ANCF)which uses cubic interpolation at the longitudinal direction and linear at the transverse direction is proposed.The element can accurately discretize the geometry represented by the Bézier volume with the same basis function order.The continuity property of the proposed beam element is verified.Advantages of the proposed element can be found in the application of leaf spring modeling.The parabolically varying thickness of the leaf can be accurately described.Components in leaf spring such as the spring eye and the rubber bushing can be assembled efficiently since the proposed element can be connected at any direction.The ANCF reference node is used to represent the rigid components and the revolute joints in the vehicle suspension system.Static I-shaped cross-section cantilever beam and flexible pendulum model are used to test the accuracy and dynamic performance of the proposed solid-beam element.The leaf spring model shows the flexibility of the element in modeling the complex mechanical system and the balance between the accuracy and the efficiency.展开更多
基金Acknowledgements - This work was supported by the National Natural Science Foundation of Chin a (Grant No.59875075) and the Univ
文摘Cold roll forming is a complicated metal processing, and its is very difficult to simulate the forming process. Based on the Updated-Lagrange method in the deformation mechanics, an elastic-plastic large deformation spline finite strip method is developed to analyze cold roll forming of a thin channel section. The longitudinal membrane strain values on the edge of the deformed strip for four one-pass sequences in different fold angles are got. Simulated results are compared with the results from previously conducted experiments. The deviation of the simulated peak strain values is within 30% compared with the experimental results.
文摘Partially filled pipeflows were encountered in drainage systems belonging to a family of unsteady flow problems. Basic equations were developed and numerically solved also by the characteristic different methods with time-line interpolation scheme. The boundary conditions for the inflow, outflow, moving hydraulic jump and junctions were developed experimentally and numerically. Full scale model experiments were carried out. It is consequently clarified that numerical model is capable of predicting flow characteristics in realistic drainage networks.
文摘The mathematical model of conical involute gears is developed based on the theory of gearing and the generating mechanism. Tooth contact analysis （TCA） is performed to examine the meshing and bearing contact of the conical involute gear pairs with intersected and crossed axes. In addition, the principal directions and curvatures of the gear surfaces are investigated and the contact ellipses of the mating tooth surfaces are also studied. Finally, the numerical illustrative examples are provided to demonstrate the computational results, test gears are made for tooth-bearing tests, and the conclusion is verified that the theory has the applicability.
基金This project is financially supported by the National Science Foundation of China
文摘This paper presents a new finite element method for solving static and dynamic problems in laying operation of pipelines. The effect of the viscoelastic soil behavior is considered by using the Pasternak foundation model. Some examples are also presented.
文摘OBJECTIVE: The characteristics of lip-mouth region including the soft and hard tissues in smiling position with frontal fixed position photographic computer-aided analysis were studied. METHODS: The subjects were 80 persons (40 male and 40 females, age range: 17 to approximately 25 years) with acceptable faces and individual normal occlusions. The subjects were asked to take maximum smiling position to accept photographic measurement with computer-aided analysis. RESULTS: The maximum smile line could be divided into 3 categories: low smile line (16.25%), average smile line (68.75%), and high smile line (15%). CONCLUSION: The method adopting maximum smiling position to study the lip-month region is reproducible and comparable. This study would be helpful to provide a quantitative reference for clinical investigation, diagnosis, treatment and efficacy appraisal.
文摘In this paper the modern electron optical equipment is used to translate the clear image of speed moving bubbles in bubbling liquid on a sieve tray into the digital information stored in computer, and the computer aided image processing technique is utilized to measure the bubble size distributions and interfacial areas under various operating conditions. And the dynamic behavior of bubbles in turbulent liquid is analyzed theoretically; the mechanism of bubble deformation and breakage is explored on the basis of Kolmogoroff′s isotropic turbulence hypothesis; the mathematical model for predicting the gas liquid interfacial area is proposed. The comparison between the simulated results and the experimental data shows that the model is higher in accuracy, simple in form and convenient in use.
基金This project is supported by the National Science Foundation "Tian Yuan" Terms and LNM Institute of Mechanics Academy of ScienceThis project is supported by the NationalYunnan Province Natural Science Foundation of China
文摘In this paper a mathematical model of AIDS is investigated.The conditions of the existence of equilibria and local stability of equilibria are given.The existences of transcritical bifurcation and Hopf bifurcation are also considered.in particular,the conditions for the existence of Hopf bifurcation can be given in terms of the coefficients of the characteristic equation.The method extends the application of the Hopf bifurcation theorem to higher differential equations which occur in biological models,chemical models,and epidemiological models etc.
文摘In the present paper an unsteady flow of polymer fluid, i.e. non-Newtonian fluid is studied. The constitutive equation of upper-convected Maxwell fluid is used. The variational approach due to Kantorovich is used for the unsteady problem of the fluid. A special computer program `MACSYMA' is used to get the different approximation of the method of Kantorovich. The present method developed is called Computational Analytical Method which is available for the scientific research.
文摘With the help of the decline method, a computer-aided analysis program of Christofell equation is described which makes it possible to calculate elastic and viscous constants of crystals precisely and easily. The elastic constants of LiNbO3 and Bi12 GeO20 crystals are calculated with an Apple - II computer and the Fortran program suggested; the calculated data are compared with the values achieved by others.
基金supported by the National Natural Science Foundation of China(Grant No.11802072)Key Project of Science and Technology of Hu'nan Province(Grant No.2018GK1040).
文摘An eight-node solid-beam element based on absolute nodal coordinate formulation(ANCF)which uses cubic interpolation at the longitudinal direction and linear at the transverse direction is proposed.The element can accurately discretize the geometry represented by the Bézier volume with the same basis function order.The continuity property of the proposed beam element is verified.Advantages of the proposed element can be found in the application of leaf spring modeling.The parabolically varying thickness of the leaf can be accurately described.Components in leaf spring such as the spring eye and the rubber bushing can be assembled efficiently since the proposed element can be connected at any direction.The ANCF reference node is used to represent the rigid components and the revolute joints in the vehicle suspension system.Static I-shaped cross-section cantilever beam and flexible pendulum model are used to test the accuracy and dynamic performance of the proposed solid-beam element.The leaf spring model shows the flexibility of the element in modeling the complex mechanical system and the balance between the accuracy and the efficiency.
