In order to study the sliding characteristics when the cable structures are connected with other rods, a string of sliding cable dements （SCE） consisting of one active threenode SCE passing through the sliding point...In order to study the sliding characteristics when the cable structures are connected with other rods, a string of sliding cable dements （SCE） consisting of one active threenode SCE passing through the sliding point and multiple inactive two-node SCEs is put forward. Based on the updated Lagrangian formulation, the geometric nonlinear stiffness matrix of the three-node straight sliding cable dement is deduced. The examples about two-span and three-span continuous cable structures are studied to verify the effectiveness of the derived SCE. Comparing the cable tension of SCE with the existing research results, the calculating results show that the error is less than 1%. The sliding characteristics should be considered in practical engineering because of the obvious difference between the cable tension of the SCE and that of the cable element without considering sliding characteristics.展开更多
This article gives a unified geometric interpretation of the second Matrix-AKNS hierarchies via Schroedinger flows to symmetric spaces of Kaehler and paraKaehler types.
Nonlinear forced vibrations and natural frequency of sandwich functionally graded material doubly curved shallow shell with a rectangular base are investigated. The sandwich functionally graded material(FGM) doubly cu...Nonlinear forced vibrations and natural frequency of sandwich functionally graded material doubly curved shallow shell with a rectangular base are investigated. The sandwich functionally graded material(FGM) doubly curved shell is subjected to a harmonic point load at centre. The sandwich doubly curved shell with homogeneous face sheets and FGM face sheets is considered respectively when the natural frequencies are studied. Reddy's third order shear deformation theory is expanded in which stretching effects in thickness are considered by introducing the secant function. Hamilton's principle and von-Karman type nonlinear geometric equation are applied to obtain partial differential equation of the FGM sandwich doubly curved shell. Comparative studies with other shear deformation theories are carried out to validate the present formulation. Navier method is used to discuss the natural vibration frequencies of the FGM sandwich doubly curved shell. Numerical simulation is applied to demonstrate the nonlinear dynamic responses of the FGM sandwich doubly curved shell. Multiple periods, quasi-period and chaos are detected for the dynamic system for different core thickness.展开更多
A wave equation with variable coefficients and nonlinear boundary feedback is studied. The results of energy decay of the solution are obtained by multiplier method and Riemann geometry method. Previous results obtain...A wave equation with variable coefficients and nonlinear boundary feedback is studied. The results of energy decay of the solution are obtained by multiplier method and Riemann geometry method. Previous results obtained in the literatures are generalized in this paper.展开更多
Based on the consistent symrnetrizable equilibrated （CSE） corotational formulation, a linear triangular flat thin shell element with 3 nodes and 18~ of freedom, constructed by combination of the optimal membrane ele...Based on the consistent symrnetrizable equilibrated （CSE） corotational formulation, a linear triangular flat thin shell element with 3 nodes and 18~ of freedom, constructed by combination of the optimal membrane element and discrete Kirchhoff trian- gle （DKT） bending plate element, was extended to the geometric nonlinear analysis of thin shells with large rotation and small strain. Through derivation of the consistent tangent stiffness matrix and internal force vector, the corotational nonlinear finite element equations were established. The nonlinear equations were solved by using the Newton-Raphson iteration algorithm combined with an automatic load controlled technology. Three typical case studies, i.e., the slit annular thin plate, top opened hemispherical shell and cylindrical shell, validated the accuracy of the formulation established in this paper.展开更多
基金The National Natural Science Foundation of China (No.51308193)China Postdoctoral Science Foundation (No.20110491342)+1 种基金Jiangsu Planned Projects for Postdoctoral Research Funds(No.1101018C)the Science and Technology Project of State Grid Corporation of China(No.SGKJ[2007]116)
文摘In order to study the sliding characteristics when the cable structures are connected with other rods, a string of sliding cable dements （SCE） consisting of one active threenode SCE passing through the sliding point and multiple inactive two-node SCEs is put forward. Based on the updated Lagrangian formulation, the geometric nonlinear stiffness matrix of the three-node straight sliding cable dement is deduced. The examples about two-span and three-span continuous cable structures are studied to verify the effectiveness of the derived SCE. Comparing the cable tension of SCE with the existing research results, the calculating results show that the error is less than 1%. The sliding characteristics should be considered in practical engineering because of the obvious difference between the cable tension of the SCE and that of the cable element without considering sliding characteristics.
文摘This article gives a unified geometric interpretation of the second Matrix-AKNS hierarchies via Schroedinger flows to symmetric spaces of Kaehler and paraKaehler types.
基金supported by the National Natural Science Foundation of China(Grant Nos.11472056 and 11472298)the Natural Science Foundation of Tianjin City(Grant No.13JCQNJC04400)
文摘Nonlinear forced vibrations and natural frequency of sandwich functionally graded material doubly curved shallow shell with a rectangular base are investigated. The sandwich functionally graded material(FGM) doubly curved shell is subjected to a harmonic point load at centre. The sandwich doubly curved shell with homogeneous face sheets and FGM face sheets is considered respectively when the natural frequencies are studied. Reddy's third order shear deformation theory is expanded in which stretching effects in thickness are considered by introducing the secant function. Hamilton's principle and von-Karman type nonlinear geometric equation are applied to obtain partial differential equation of the FGM sandwich doubly curved shell. Comparative studies with other shear deformation theories are carried out to validate the present formulation. Navier method is used to discuss the natural vibration frequencies of the FGM sandwich doubly curved shell. Numerical simulation is applied to demonstrate the nonlinear dynamic responses of the FGM sandwich doubly curved shell. Multiple periods, quasi-period and chaos are detected for the dynamic system for different core thickness.
基金This research is supported by the National Science Foundation of China under Grant No. 60774014 and the Science Foundation of Shanxi Province under Grant No. 2007011002. The authors would like to express their sincere thanks to Shugen CHAI for his valuable comments and useful suggestions on the manuscript of this work.
文摘A wave equation with variable coefficients and nonlinear boundary feedback is studied. The results of energy decay of the solution are obtained by multiplier method and Riemann geometry method. Previous results obtained in the literatures are generalized in this paper.
基金supported by the National Natural Science Foundation of China (Grant No. 51075208)the Innovation Project for Graduate Students of Jiangsu Province (Grant No. CX07B-162z)the Fund for Innovative and Excellent Doctoral Dissertation of NUAA (Grant No.BCXJ07-01)
文摘Based on the consistent symrnetrizable equilibrated （CSE） corotational formulation, a linear triangular flat thin shell element with 3 nodes and 18~ of freedom, constructed by combination of the optimal membrane element and discrete Kirchhoff trian- gle （DKT） bending plate element, was extended to the geometric nonlinear analysis of thin shells with large rotation and small strain. Through derivation of the consistent tangent stiffness matrix and internal force vector, the corotational nonlinear finite element equations were established. The nonlinear equations were solved by using the Newton-Raphson iteration algorithm combined with an automatic load controlled technology. Three typical case studies, i.e., the slit annular thin plate, top opened hemispherical shell and cylindrical shell, validated the accuracy of the formulation established in this paper.
