Applied Mechanics and Materials Vols. 353-356

Abstract: Consider the rod on elastic foundation. Its discrete model is the simply connected spring-mass system with partial mass connected to the ground. The inverse mode problem of constructing the physical elements of the system from two eigenpairs, the spring stiffness of the system is considered. The necessary and sufficient conditions for constructing a physical realizable system with positive mass and stiffness elements are established. If these conditions are satisfied, the rod on the elastic foundation may be constructed uniquely. The numerical methods and examples are given finally.

Abstract: The vibration method is usually used for field measurement of cable tension of cable system bridges. The cable tension evaluation method is mostly based on the simple taut string theory. However, the simple theory may cause unacceptable errors in many applications especially for the cables with big bending stiffness and two ends fixed boundary conditions. In this paper a cable tension estimation method based on iterative algorithm and optimization algorithm is presented and implemented using finite element method and ANSYS soft ware. Compared with the analytical method and empirical formulas the method presented in this paper is more convenient and the application range is more extensive. The accuracy of the method has been verified by a set of test. In the end, the method is used to estimate the cable tension of a tied-arch bridges suspenders.

Abstract: The most widely used calculation method for bridge transverse distribution coefficient based on plate theory is G-M method. The twisted parameter and bending stiffness parameter are firstly obtained in its calculation process, the distribution coefficient can be determined through inquiring the tables established by Guyon and Massonnet. The work for this computation is huge and the errors are inevitably exist in the stage of inquiring tables. Therefore, an analytical method is proposed in this paper, the partial differential equations of deflection surface can be acquired through analysis and corresponding calculating program is prepared. Numerical simulation of simply supported bridge is presented for validating its feasibility.

Abstract: Under seismic action, it is easy for the traditional steel nodes to produce a greater degree of brittle failure. The assembly of steel outer annual node after its manufacture in the factory reduces the shear deformation of the structure, and improves the rigidity of the node. The destruction of the structure occurs mainly in some critical parts. By making a calculation of critical connections in this article, we can make the structure more secure.

Abstract: The quasi-Greens function method (QGFM) is applied to solve the bending problem of simply supported polygonal shallow spherical shells on Pasternak foundation. A quasi-Greens function is established by using the fundamental solution and the boundary equation of the problem. And the function satisfies the homogeneous boundary condition of the problem. Then the differential equation of the problem is reduced to two simultaneous Fredholm integral equations of the second kind by the Greens formula. The singularity of the kernel of the integral equation is overcome by choosing a suitable form of the normalized boundary equation. The comparison with the ANSYS finite element solution shows a good agreement, and it demonstrates the feasibility and efficiency of the proposed method.

Abstract: A simple and efficient explicit scheme of triangular planar element with rotation degrees of freedom is proposed in this paper. The basic fundamental solutions of plane elasticity problem based on Airy stress functions are used as trial functions to construct triangular element with drilling degrees of freedom. During the construction of element model, the explicit expression of element stiffness matrix is deduced by means of triangular area coordinates integration method, instead of numerical integration method. Numerical calculation indicates that the element constructed in this paper is of high precision but less computational cost.

Abstract: The distinctive paper is devoted to correct wavelet-based multilevel discrete-continual methods for local solution of boundary problems of structural analysis. Initial discrete-continual operational formulation of the considering problem and corresponding operational formulation with the use of wavelet basis are presented. Due to special algorithms of averaging within multigrid approach, reduction of the problem is provided. Resultant multipoint boundary problem of structural mechanics for system of ordinary differential equations with piecewise-constant coefficients is given.

Abstract: Kinematic indeterminate systems under construction state and even in-service state may undergo marked displacement. The mathematical model is developed for determination of displacement in kinematic indeterminate systems. The proposed procedures are extended to describe unloading process from prestressed to unstressed state, with particular emphasis on the applications of the unstressed state analysis of practical interest.

Abstract: The compressive height of reinforced concrete flexural members in service stage is generally obtained by equations based on the concept, moment-of-area of conversion area with respect to the neutral axis in tension zones equaling to that in compression zones. In this paper a specific calculation method of compressive height for singly or doubly reinforced rectangular and T-shaped cross sections is proposed.

Abstract: Based on the Loves shell theory, relationship between bending solutions of functionally graded materials (FGM) and homogenous circular cylindrical shells was studied. By comparing the displacement-type governing equations for axially symmetrically bending of FGM and homogenous circular cylindrical shells, an analogous transform relation between the deflections of FGM circular cylindrical shell and those of homogenous one was obtained. By giving the material properties of FGM circular cylindrical shell changing as continuous functions in the thickness direction, the corresponding transition factor between the solutions of the two kind circular cylindrical shells were derived, which reflect the non-uniform properties of the functionally graded material circular cylindrical shell. Numerical example shows that the numerical solutions of the maximum of non-dimensional deflections are almost in agreement with the transformational solutions when n equals approximately 5, where n is the volume fraction index. As a result, solutions for axially symmetrically bending of a non-homogenous circular cylindrical shell can be reduced to that of a homogenous one and the calculation of the transformation factors.