Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ...Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ordinary solution techniques lead to instability near the limit points and also have problems in case of snap-through and snap-back. Thus they fail to predict the complete load-displacement response. The arc-length method serves the purpose well in principle, received wide acceptance in finite element analysis, and has been used extensively. However modifications to the basic idea are vital to meet the particular needs of the analysis. This paper reviews some of the recent developments of the method in the last two decades, with particular emphasis on nonlinear finite element analysis of reinforced concrete structures.展开更多
Under the' assumption of linearization of the free-surface condition, making use of Green's function method and the convolution theorem, analytic solutions of perturbation velocity potentials which correspond ...Under the' assumption of linearization of the free-surface condition, making use of Green's function method and the convolution theorem, analytic solutions of perturbation velocity potentials which correspond to three dimensional unsteady thickness problem and lifting problem caused respectively by arbitrary motions of a body and a hydrofoil beneath the water surface can be achieved in the closed form, In general, the whole perturbation velocity potential consists of three terms, namely φ=φ1+φ2+φ3 , where φ1 denotes the induced velocity potential of the surface singularity distribution in an unbounded fluid, φ2 denotes its mirror image and φ3 denotes that of wave formation which includes the memory effect of the action of the singularity distribution. Utilizing the polynomial expansion of sin[(t-τ)] , the similarity between φ2 and φ3 is discovered and thus a simpler differential relation between them is obtained. Applying this relation, the amount of work in calculation of φ3 which is the most time-consuming one will be reduced significantly. It is favorable not only for dealing with unsteady wave- making problems but also for solving the steady ones in virtue of evading a major difficulty which has to be encountered during the evaluation of an improper inte- gral containing a singularity in the Green's function. The limitation of this new technique turns out to be its slower convergence as the Froude number is lower.展开更多
By applying iterative technique,we obtain the existence of positive solutions for a singular Riemann-Stieltjes integral boundary value problem in the case that f（t,u） is non-increasing respect to u.
In this paper, we are concerned with the symmetric positive solutions of a 2n-order boundary value problems on time scales. By using induction principle,the symmetric form of the Green＇s function is established. In o...In this paper, we are concerned with the symmetric positive solutions of a 2n-order boundary value problems on time scales. By using induction principle,the symmetric form of the Green＇s function is established. In order to construct a necessary and sufficient condition for the existence result, the method of iterative technique will be used. As an application, an example is given to illustrate our main result.展开更多
文摘Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ordinary solution techniques lead to instability near the limit points and also have problems in case of snap-through and snap-back. Thus they fail to predict the complete load-displacement response. The arc-length method serves the purpose well in principle, received wide acceptance in finite element analysis, and has been used extensively. However modifications to the basic idea are vital to meet the particular needs of the analysis. This paper reviews some of the recent developments of the method in the last two decades, with particular emphasis on nonlinear finite element analysis of reinforced concrete structures.
文摘Under the' assumption of linearization of the free-surface condition, making use of Green's function method and the convolution theorem, analytic solutions of perturbation velocity potentials which correspond to three dimensional unsteady thickness problem and lifting problem caused respectively by arbitrary motions of a body and a hydrofoil beneath the water surface can be achieved in the closed form, In general, the whole perturbation velocity potential consists of three terms, namely φ=φ1+φ2+φ3 , where φ1 denotes the induced velocity potential of the surface singularity distribution in an unbounded fluid, φ2 denotes its mirror image and φ3 denotes that of wave formation which includes the memory effect of the action of the singularity distribution. Utilizing the polynomial expansion of sin[(t-τ)] , the similarity between φ2 and φ3 is discovered and thus a simpler differential relation between them is obtained. Applying this relation, the amount of work in calculation of φ3 which is the most time-consuming one will be reduced significantly. It is favorable not only for dealing with unsteady wave- making problems but also for solving the steady ones in virtue of evading a major difficulty which has to be encountered during the evaluation of an improper inte- gral containing a singularity in the Green's function. The limitation of this new technique turns out to be its slower convergence as the Froude number is lower.
基金supported by Program for Scientific research innovation team in Colleges and universities of Shandong Provincethe Doctoral Program Foundation of Education Ministry of China(20133705110003)+1 种基金the Natural Science Foundation of Shandong Province of China(ZR2014AM007)the National Natural Science Foundation of China(11571197)
文摘By applying iterative technique,we obtain the existence of positive solutions for a singular Riemann-Stieltjes integral boundary value problem in the case that f（t,u） is non-increasing respect to u.
基金Supported by NNSF of China(11201213,11371183)NSF of Shandong Province(ZR2010AM022,ZR2013AM004)+2 种基金the Project of Shandong Provincial Higher Educational Science and Technology(J15LI07)the Project of Ludong University High-Quality Curriculum(20130345)the Teaching Reform Project of Ludong University in 2014(20140405)
文摘In this paper, we are concerned with the symmetric positive solutions of a 2n-order boundary value problems on time scales. By using induction principle,the symmetric form of the Green＇s function is established. In order to construct a necessary and sufficient condition for the existence result, the method of iterative technique will be used. As an application, an example is given to illustrate our main result.
