Advanced Materials Research Vol. 743

Abstract: Based on ANSYS software, the solid modeling method was performed to build the half model of bi-prestressed concrete beam. And the solution for solve the problem such as the constitutive equation, failure criteria , the method of modeling,the infliction method of prestressed was summarized in this paper. The heating-cooling method was used to achieve the bi-prestressed.The simulate method was reasonable while the built mode was performed to simulate the pre-arch and bearing capacity, simulate the pre-arch and bearing capacity of pre-pressed bi-prestressed concrete beam by FEM software ,and compared with the experiment results. And summarized the handling of the constitutive equation,failure criteria,the infliction method of prestressed, the method of modeling ,and so on. All of the method will provide reference for the research of Bi-prestressed concrete beam.

Abstract: Large steel crude oil tanks constructed in soft foundations are susceptible to various types of settlement deflections. The most common type is planar inclined foundation. In this paper, the FEM is used for the study of deformation characteristic and stress distribution of large steel crude oil tank under the planar inclined foundation approaching to critical value. Results show that deformation characteristic of tank is unevenness; max stress in tank shell occurs in middle-low part of floating roof tank; the ultimate value of large steel crude oil tank under the planar inclined foundation is 0.89m.

Abstract: The objective of the present work is to propose a new composite seismic isolation system device based on the cable-sliding friction aseismic bearing (CSFAB). Multi-chip steel spiral spring (MSSS) are characterized by unique mechanical properties due to elastic recovery capability. An isolation bearing system based on a MSSS elastic effect is intended to provide recovery properties to reduce or eliminate the residual deformations. The device concept is based on two separate systems, one to transmit the vertical load and to act as a lateral restrainer at meantime, the other contributes to the automatic reset functions in the system. This article presents in detail the mechanical components of the innovative device focusing on its main properties. The load-deformation curve established in this paper is verified to be efficient in describing the mechanical characteristics of the device through experiment. The results could provide reference for study and application of the new composite seismic isolation system.

Abstract: This paper represents the introduction to the selection, construction scheme and design of No. 0 support material for the main beam of Jianyi Bridge in Fengcheng City, the computational check on the bearing capacity of the support structure through MIDAS/Civil V2006 Modeling, then the bearing capacity of all the members can meet the requirements.

Abstract: In this paper, an alternative aseismic system for bridge with pile-cap foundation called a separated pile-cap with proper material set in the gap layer was proposed. To simulate the system, a 3-dimensional finite element model for a continuous beam bridge was built. The seismic responses of the model, including behavior of the restrainer, moment at the bottom of the pier and pullout force of the piles with different restrainer lengths under 3 longitudinal artificial earthquake waves were analyzed. The results show that this system can reduce the seismic response significantly.

Abstract: This paper focuses on the structural design for Lijiang Sports Center Stadium, reasonable structure partition of the stadium and the combined analysis of the lower part of reinforced concrete structure with the upper part of steel marguise. Besides, foundation design under larger eccentric loads and horizontal shear forces as well as the selection of pile foundation design are also investigated.

Abstract: The paper deals with the problems of the load-carrying capacity of steel and steel-concrete composite members composed of high-strength materials, subjected to compression. The attention is mainly paid to the buckling resistance in the connection with member imperfections, which are usually covered by the equivalent initial geometrical imperfection expressed as the maximal initial member curving in the mid-length of the buckled member subjected to compression. The paper is oriented to the analytical solution of the initial eccentricity based on the conception of the buckling strength and to the possibilities how to verify the initial imperfection experimentally. The analysis of this problem is shown on the examples of steel and steel-concrete composite columns represented by open HEA cross-section and by the same cross-sections partially encased by normal-strength and high-strength concrete. Using test results of the specimens subjected to compression the comparison of actual values of initial imperfections with the corresponding theoretical values is presented here.

Abstract: In this paper the study on lateral flexural-torsional buckling of steel sigma-cross-section beams with web holes will be presented. The analysis of corresponding stability problem is based on general approach derived for a group of beams including at least mono-symmetric sections loaded transversally to their plane of symmetry. The effective flexural and torsional stiffness of steel beams with holes has been verified by tests. The results of theoretical analysis were compared with specification design procedure and also with actual behaviour of set of beams investigated by experiments. The study conclusions aim to become the background of the supplements to specified provisions for the design of steel structures.

Abstract: The ZnFe₂O₄ nanometer powders were prepared by EDTA sol-gel method. The samples were characterized by DTA, FT-IR, XRD techniques. The preparation process, the best heat-treatment temperature and the electrochemical performance had been studied. The results show that the spherical nanometer powders can be obtained and the best heat-treatment temperature is 900°C. The particle size is about 10nm and Ea is 0.88 eV.

Abstract: Functional modification of the surface of Fe₃O₄ nanoparticles was studied using silane coupling reagent A151. The modified and unmodified nanoparticles were characterized by FT-IR, XPS, TEM, DLS and VSM. Both of the unmodified and modified Fe₃O₄ particles show superparamagnetic behavior, and their saturation magnetic values were determined to be 81.14 emu/g and 73.0 emu/g, respectively. A151 was adsorbed on surface and formed chemical bond to be steric hindrance repulsion which prevented nanoparticles from reuniting. The dispersion properties of modified Fe₃O₄ particles were associated with the mass ratio of A151/Fe₃O₄.