The cavitated bifurcation problem in a solid sphere composed oftwo compressible hyper-elas- tic materials is examined. Thebifurcation solution for the composed sphere under a uniform radialtensile boundary dead-load i...The cavitated bifurcation problem in a solid sphere composed oftwo compressible hyper-elas- tic materials is examined. Thebifurcation solution for the composed sphere under a uniform radialtensile boundary dead-load is obtained. The bifurcation curves andthe stress contributions subsequent to the cavita- tion are given.The right and left bifurcation as well as the catastrophe andconcentration of stresses are ana- lyzed. The stability of solutionsis discussed through an energy comparison.展开更多
In this paper,the problem of axially symmetric deformation is examined for a composite cylindrical tube under equal axial loads acting on its two ends,where the tube is composed of two different incompressible neo-Hoo...In this paper,the problem of axially symmetric deformation is examined for a composite cylindrical tube under equal axial loads acting on its two ends,where the tube is composed of two different incompressible neo-Hookean materials.Significantly,the implicit analytical solutions describing the deformation of the tube are proposed.Numerical simulations are given to further illustrate the qualitative properties of the solutions and some meaningful conclusions are obtained.In the tension case,with the increasing axial loads or with the decreasing ratio of shear moduli of the outer and the inner materials,it is proved that the tube will shrink more along the radial direction and will extend more along the axial direction.Under either tension or compression,the deformation along the axial direction is obvious near the two ends of the tube,while in the rest,the change is relatively small.Similarly,for a large domain of the middle part,the axial elongation is almost constant;however,the variation is very fast near the two ends.In addition,the absolute value of the axial displacement increases gradually from the central cross-section of the tube and achieves the maximum at the two endpoints.展开更多
Dynamical cavitation and oscillation of an anisotropic two-family fiber-reinforced incompressible hyper-elastic sphere subjected to a suddenly applied constant boundary dead load are examined within the framework of f...Dynamical cavitation and oscillation of an anisotropic two-family fiber-reinforced incompressible hyper-elastic sphere subjected to a suddenly applied constant boundary dead load are examined within the framework of finite elasto-dynamics.An exact differential equation between the radius of the cavity and the applied load is obtained.The curves for the variation of the maximum radius of the cavity with the load and the phase diagrams are obtained by vibration theories and numerical computation.It is shown that there exists a critical value for the applied load.When the applied load is larger than the critical value,a spherical cavity will suddenly form at the center of the sphere.It is proved that the evolution of the cavity radius with time follows that of nonlinear periodic oscillation,and oscillation of the anisotropic sphere is not the same as that of the isotropic sphere.展开更多
基金the National Natttral Science Foundation of China(No.19802012)
文摘The cavitated bifurcation problem in a solid sphere composed oftwo compressible hyper-elas- tic materials is examined. Thebifurcation solution for the composed sphere under a uniform radialtensile boundary dead-load is obtained. The bifurcation curves andthe stress contributions subsequent to the cavita- tion are given.The right and left bifurcation as well as the catastrophe andconcentration of stresses are ana- lyzed. The stability of solutionsis discussed through an energy comparison.
文摘为了探究海拔对我国西南高寒地区植物稳定碳同位素组成特征及水分利用效率的影响,本研究以梅里雪山东坡不同海拔(2200、2500、2700、3000、3200和4200 m)上不同功能型植物为对象,分析了不同光合途径(C3和Crassulacean acid metabolism,CAM)植物和C3植物中不同生活型(灌木、阔叶乔木和针叶乔木)植物叶片稳定碳同位素组成特征(δ^(13)C_(p))及内在水分利用效率(intrinsic water use efficiency,iWUE)随海拔梯度的变化。结果表明:(1)梅里雪山东坡C3植物叶片的δ^(13)C_(p)值分布范围在-26.72‰~-31.67‰,均值为-29.12‰,而CAM植物的δ^(13)C_(p)值分布范围在-13.24‰~-14.59‰,均值为-13.77‰;(2)CAM植物δ^(13)C_(p)值和iWUE显著高于C3植物,其中,C3植物中不同生活型植物δ^(13)C_(p)和iWUE值呈现灌木>阔叶乔木>针叶乔木的变化规律;(3)海拔3200 m以下乔木和灌木植物δ^(13)C_(p)和iWUE值随海拔升高而降低,主要受土壤水分的影响,3200 m以上灌木植物δ^(13)C_(p)和iWUE值随海拔升高有增大的趋势,可能受温度的调控。梅里雪山东坡不同功能型植物水分利用效率对海拔梯度的响应反映了不同植物对高寒山地气候不同的适应性。
基金supported by the National Natural Science Foundation of China(Grant Nos.10872045 and 11232003)the Program for New Century Excellent Talents in University(Grant No.NCET-09-0096)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.DC120101121)the Program for Liaoning Excellent Talents in University(Grant No.LR2012044)
文摘In this paper,the problem of axially symmetric deformation is examined for a composite cylindrical tube under equal axial loads acting on its two ends,where the tube is composed of two different incompressible neo-Hookean materials.Significantly,the implicit analytical solutions describing the deformation of the tube are proposed.Numerical simulations are given to further illustrate the qualitative properties of the solutions and some meaningful conclusions are obtained.In the tension case,with the increasing axial loads or with the decreasing ratio of shear moduli of the outer and the inner materials,it is proved that the tube will shrink more along the radial direction and will extend more along the axial direction.Under either tension or compression,the deformation along the axial direction is obvious near the two ends of the tube,while in the rest,the change is relatively small.Similarly,for a large domain of the middle part,the axial elongation is almost constant;however,the variation is very fast near the two ends.In addition,the absolute value of the axial displacement increases gradually from the central cross-section of the tube and achieves the maximum at the two endpoints.
基金supported by the National Natural Science Foundation of China (Grant Nos.10772104 and 10872045)the innovation project of Shanghai Municipal Education Commission (Grant No.09YZ12)Shanghai Leading Academic Discipline Project (Grant No.S30106)
文摘Dynamical cavitation and oscillation of an anisotropic two-family fiber-reinforced incompressible hyper-elastic sphere subjected to a suddenly applied constant boundary dead load are examined within the framework of finite elasto-dynamics.An exact differential equation between the radius of the cavity and the applied load is obtained.The curves for the variation of the maximum radius of the cavity with the load and the phase diagrams are obtained by vibration theories and numerical computation.It is shown that there exists a critical value for the applied load.When the applied load is larger than the critical value,a spherical cavity will suddenly form at the center of the sphere.It is proved that the evolution of the cavity radius with time follows that of nonlinear periodic oscillation,and oscillation of the anisotropic sphere is not the same as that of the isotropic sphere.
