Applied Mechanics and Materials Vols. 580-583

Abstract: An axial symmetry elasticity model of the concrete short column which is pushed out from over-thick steel tube is set up, and the equations of displacement method are derived. The experiment of push-out test of the short column was carried out. On the base of the test, the adhesive thin-layer between the concrete and the over-thick steel tube is introduced. The experimental results show that the shearing stress in the adhesive thin-layer is uniform along the height, which is coincide with the results obtained by the axial symmetry elasticity model of the concrete short column set up in this paper. Therefore, the adhesive shearing stress between steel tube and concrete can be precisely measured by the push-out test of the concrete short column and the relation of shearing stress-shearing strain of the adhesive thin-layer can be determined.

Abstract: Numerical simulations play a significant role in explosion in a mass of soil due to an underground explosive. Common methods available in hydrocode for fluid-solid coupling process are contact algorithm, Lagrange algorithm, and Arbitrary Lagrange-Euler (ALE) algorithm. A numerical simulation of explosion process with concentrated charge in a mass of soil was carried out by using three methods in this paper. The dynamic response of soil medium, the formation and development law of explosion cavity and the explosion wave propagation law in soil were simulated. Merits and drawbacks of three different methods are analyzed in the aspect of modeling, simulation results and computing cost.

Abstract: The stability of submerged functionally graded (FG) cylindrical shell under hydrostatic pressure is examined in this paper. Based on the Flügges shell theory, the coupled frequency of submerged FG cylindrical shell is obtained, using wave propagation method and Newton method. Then the critical pressure of FG cylindrical shells is given by applying linear fitting method. Results are compared to known solutions, where these solutions exist. The effects of constituent materials, volume fraction, boundary condition and dimensions on the critical pressures of submerged FG cylindrical shell are illustrated by examples.

Abstract: This paper is devoted to correct and efficient method of local static analysis of Bernoulli beam on elastic foundation. First of all, problem discretized by finite difference method, and then transformed to a localized one by using the Haar wavelets. Finally, imposing an optimal reduction in wavelet coefficients, the localized, reduced results can be obtained. It becomes clear after comparison with analytical solutions, that the localization of the problem by multiresolution wavelet approach gives exact solution in desired regions of beam even in high level of reduction in wavelet coefficients. This localization can be applied to any arbitrary region of the beam by choosing optimum reduction matrix and obtaining exact solutions with an acceptable reduced size of the problem.

Abstract: Buckling behavior of functionally graded materials cylindrical shell under pure bending is studied in this paper. The stability equations of functionally graded materials cylindrical shell are derived using the classical plate and shell theory with Kirchhoff hypothesis, importing the bending boundary condition to obtain the critical buckling load. The result shows that the critical moment is linear with the radius, quadratic with the thickness and irrelevant with the length of the cylindrical shell. In addition, the critical moment is decreased by increasing the power law index of the material bulk, trending to a constant finally.

Abstract: Here computational models of contact of elastic systems with the contact finite elements (CFE) in a 2D or 3D frame-rod systems are reviewed. The solution is based on the method of the step-by-step analysis taking into account the character of loading, the complicated conditions of the contact and other factors consideration of which approaches the calculation circuit of the task to the real operating conditions of any structures or construction

Abstract: Conventional and a class of domain decomposition finite element–boundary element coupling (FEM–BEM) methods are reviewed. This is Part I of two papers. In Part II, a review of the mixed Dirichlet-Neumann domain decomposition FEM-BEM coupling method is presented and optimal dynamic values of the relaxation parameters for the mixed Dirichlet-Neumann FEM-BEM coupling method are, furthermore, derived.

Abstract: Part I of this paper presents an overview of the conventional and a class of domain decomposition finite element-boundary element coupling methods. In this part, a review of the mixed Dirichlet-Neumann domain decomposition coupling method, procedures for dynamic calculation of relaxation parameters for the mixed Dirichlet-Neumann FEM-BEM coupling method and an example application are presented.

Abstract: A state space method has been put forward for finding the deformations and internal forces of piles subjected to lateral loads. First of all, a pile was divided into a number of pile segments, on which the foundation reaction coefficients were viewed as a constant based on the three parameter method. Secondly, state space equations of all the pile segments were established according to Euler-Bernoulli’s beam theory and the equilibrium conditions of a pile segment. At last, a state space solution of a pile subjected to lateral loads was obtained using the boundary conditions at the top and bottom end of the pile and the continuous conditions at the interfaces between two adjacent segments. Numerical results show that the state space solution agrees well with the semi-analytical one, and all the computational formula, procedure and programming are very simple.

Abstract: Downburst is a strong downdraft thunderstorm in the ground formed after the violent impact and spread along the ground very sudden and destructive winds near the ground short. From an engineering point of view for the structure of wind-resistant design, researching downburst wind field characteristics and ultimately determining a reasonable downburst wind profile is one of the core objectives of the study. Terrain conditions are the major factors of downburst wind field characteristics based on the typical mountain terrain on the wind storm flow condition, this paper established typical 2D slope mountain terrain model, using the method of computational fluid dynamics to calculate the velocity contours and pressure cloud in different locations of the mountain. Finally we get the two-dimensional slope typical mountain terrain wind field distribution.