Advanced Materials Research Vols. 163-167

Abstract: Double-tube buckling restrained braces with contact ring is a new buckling-restrained brace (BRBs), and is a refinement of double-tube buckling restrained braces. Based on the theory of the finite element method, the finite element entity model of double-tube buckling restrained brace with contact-ring has been made. The double-tube buckling restrained braces is systematically analyzed and computed. The analysis results indicate that this kind of buckling restrained brace has good energy dissipation and restoring force characteristics, and can overcome the difficulty in connection.

Abstract: In practice most connections actually show semi-rigid deformation behavior that can contribute substantially to overall displacements of the structure and to the distribution of member forces. So it is very necessary that studying the behavior of these semi-rigid connections under cyclic reversal loading. Two full-scale specimens of top-mounted-angle using H-section member had been conducted. The specimens were subjected to cyclic reversal loading simulating earthquake effects on a steel moment-resisting force. The objective of the work is to determine the behavior of these connections under cyclic reversal loading well into the inelastic range and to ascertain the effect of design parameters such as column flange stiffener, pre-tension of bolts and the top-mounted-angle steel flange thickness on the overall behavior. Observations were made concerning the response of the connections and its elements in terms of strength, stiffness and energy dissipation. Information on the design of these connections is presented. It is concluded that top-mounted-angle connections can possess the relative high stiffness, strength and excellent ductility as moment-resisting components in the seismic design of frames. Most of the input energy was dissipated in top-mounted-angle while the column participated a little in the energy dissipation process in the test. It is analyzed that the preload of bolt, contact pressure of the components and the other components’ mechanical properties by nonlinear analysis. These consequences are good reference for the engineering design.

Abstract: The cold-formed square steel tubular with light weight has better seismic behavior and is suitable for construction in the area with high seismic fortification intensity. The reliability of joint connection greatly influence the safety reliability of structure, which’s restoring force characteristics under low cyclic loading need to be further researched. The finite element software ANSYS is used to do the research between two welded joints. The results show that : (1)Compared with typical welded joint, the ultimate bearing capacity of improved joint increase much, hysteretic curve is more plump, energy dissipation capacity enhance and stiffness degradation is slow. (2) Axial compression ratio has great influence on hysteretic behavior, bearing capacity and stiffness of common welded joints; however, there is a little effect on improved joint’s bearing capacity and stiffness. (3) After improved, the yield of joint has a longer yield platform, and under the same axial compression ratio condition, its yielding and ultimate load both obviously superior to common welded joints.

Abstract: Construction procedure of the tie arch bridge with steel-concrete composite girders affects the mechanical behavior of the whole bridge significantly. Space finite element model of Jiubao Bridge was established. Different construction procedures of the tie bars and bridge decks were proposed and the stress of upper and lower flange of the girder and the concrete bridge decks under construction schemes had been analyzed. The calculation results show that the scheme that the tie bars are stretched finally can reduce the tension stress of the bridge decks significantly. The construction scheme that the bridge decks are constructed on full space supports is favorable to the girder over the V-shaped piers.

Abstract: In this paper, taking a practical project for the study, using the finite element analysis software ANSYS, static analyses under different load conditions are performed on a single beam string structure (BSS) and a one-way beam string structure with the cooperation of the supporting structure, respectively. Moreover, influence of factors on mechanical properties of the one-way BSS with the cooperation of the supporting structure is investigated. The factors include grouting, support form, corrosion. The results can provide a reference for design and construction of the same type of structure.

Abstract: Suspended access equipment (SAE) is widely used and the impact load effect on the structure of SAE while hoisting from the ground is to be researched. In the paper, three methods were taken to analyze hoisting dynamics response of SAE, including energy equation method, mechanics model calculation and finite element method (FEM), and it turns out that FEM is the perfect one. By using FEM, structure dynamics response curve and dynamic load factor were obtained. The effect factors of structure dynamics response were also analyzed. Measures were given finally to improve the effect of hoisting impact load by analyzing displacement and acceleration response curves of SAE.

Abstract: A 3-D finite element model (FEM) using ABAQUS was introduced in this paper to simulate the post-fire behavior of composite frames with concrete-filled steel tubular (CFST) columns and steel beam with reinforced concrete slab. Accurate thermal and material model, element type, and solution method were assumed in the model considering the temperature effect during the fire. Some composite joint specimen post-fire tests were modeled using the FEM. The results obtained from the FEM were verified against those experimental results. The mechanism of the composite frame was investigated based on the FEM.

Abstract: In the paper, finite element models are established by using numerical methods to study the mechanical behavior of these kinds of connections. By discussing the range of design parameter of reduced beam section connection and widened beam section connection, stress distribution of connections and the influence of design parameter on bearing capacity at elastic stage and plastic stage are studied. The FEM models of these two kinds of connections behaved good ductility behavior. The purpose of moving plastic hinge outward from the beam and column interface is realized. Stress concentration near welds at the end of beam is reduced significantly. The bearing capacity of widened beam section connection increase obviously due to expanding the local area of beam flanges at the end of beam, but that of reduced beam section connection decrease due to trimming beam flanges. After studies, the range of design parameter of reduced beam section connection and widened beam section connection are given in the paper, and comparing with FEMA-350 [14] of American. The suggestion parameters would be useful for seismic design of steel frames.

Abstract: An analysis of a bolted endplate minor axis joint that is subjected to bending is presented in this paper. The methodology for predicting the moment-rotation relationship of such joint is based on the component method and appropriate mathematical expressions. The component of column web in bending is of special concern, by using yield line analysis and plate theory, for calculation of the resistance and the stiffness respectively. A case study is reported in this work to validate the proposed mechanical model. The result is found to be satisfactory for the prediction of moment-rotation relationship, and the validity of the proposed model is discussed.

Abstract: This paper presents an analysis on the seismic behavior of buckling-restrained brace frames（BRBFs）with different rigidity ratios by the finite element analysis software ANSYS. Based on the elastic-plastic time-history analysis, the relationships of maximum story drift ratio and the uniformity of maximum story drift ratio with different rigidity ratios are established for BRBFs subjected to large earthquakes, a reasonable range of rigidity ratio is recommended, which is the reference for the design of BRBFs.