Advanced Materials Research Vols. 163-167

Abstract: Based on seismic records with large long-period components at home and abroad, carried on uniform error correction processing and rough site classification, then, used numerical analysis software-MATLAB to calculate the average response spectrum of different types of venues, and used the least square method to do sub-fitting for them, got the long-period quasi-regulatory response spectrums of all kinds of venues; using the general-purpose finite element analysis software-ANSYS, a super high-rise building structural analysis model was established, inputted the fitted long-period seismic response spectrum and the design response spectrum of Shanghai anti-seismic standards, by comparing the results of structural seismic responeses under the two kinds of response spectrum, the long-period seismic response of super high-rise building was investigated, and some valuable conclusions were obtained for reference.

Abstract: Seismic performance of corner joints without seismic details was analyzed by software ABAQUS, the results indicated that the reinforcement ration of the girders has great effects on the failure process and seismic behavior of corner joints. Beam Haunch Method was used to strengthen these joints, and then finite element analysis was conducted for the joints with unidirectional haunched beam (UHB)and bidirectional haunched beams(BHB). It was found that the bearing capacity of joints was significantly improved but the ultimate displacement and ductility factor were slightly affected by the haunch strengthening. The strengthening effect of bidirectional haunch was obviously superior to that of unidirectional haunch.

Abstract: In this paper, we present the analysis on 3D temporal characteristics of a scale model for high-rise structure. Based on the parameter of instantaneous tangential acceleration a_T, normal acceleration a_N, Euclidean norm of acceleration vector |a|, Euclidean norm of velocity vector |v|, temporal curvature κ, κ_t, Some interesting relationships and information in depth between them would be obtain.

Abstract: This paper presents the nonlinear time-history and response spectrum analysis for a three-story steel moment frame and a braced frame by hysteretic damper against earthquake load which analyzed by SAP2000 software. The mentioned frames were analyzed by Eigenvalue method for linear analysis and Ritz-vector method for nonlinear analysis. Simulation results were presented as a time-displacement graph based on dynamic analysis, the dynamic base shear force is also calculated.

Abstract: In this paper, a new type of disk spring two-storey rolling seismic isolator was developed. The two-storey rolling isolator isolates horizontal earthquake with metallic dampers to restore to normal position, limit displacement and dissipate energy. The disk spring isolates vertical earthquake. Adopt MATLAB to build the shear model, and contrasts the earthquake response between the base-isolated structure and the unbase-isolated structure.

Abstract: An experimental study on mechanical behavior of superelastic NiTi shape memory alloy (SMA) bar subjected to torsion was made. The SMA specimen was in round bar shape, material phase was austenite and stress mode was torsion. The test was carried out by applying repeated cyclic uniform torsional load. Strain rate, strain amplitude and number of cycles were considered as test parameters. The test was described and analyzed in terms of three fundamental mechanical quantities: secant stiffness, energy loss per unit weight and equivalent damping. The test results show that SMA bar subjected to torsion, have great potential for application in seismic devices due to their considerable superelasticity and stable cyclic behaviors.

Abstract: This paper presents investigation results of buildings inYushu county, Qinghai province, which were severely damaged during the earthquake on 14 April, 2010. The M 7.1 earthquake caused large damage to buildings and serious personnel casualties in local regions. According to the different type of structures, the buildings are classified in different kinds of destroy degree and their destroy rules are summarized. On the basis of analysis and summary of the damage characteristics, the lessons are concluded and feasible countermeasures are proposed. Finally, some advices in reconstruction are given.

Abstract: A through tied arch bridge model was designed and fabricated with removable and replaceable wind bracing. Through two methods, numerical simulation and model experiments, the effects of different wind bracing forms were studied, which was to the static characteristics, dynamic characteristics and stability of such kind of bridges, and the advantages and disadvantages of different forms of wind bracing were compared, which provided the corresponding references for the selection of rational wind bracing in actual bridge project.

Abstract: This paper focuses on the analysis of dynamic characteristics of structural systems, maximum response of acceleration and maximum inter-story displacement angle etc. so as to study the seismic performance, yielding mechanism and seismic resistance capacity of the structure under the circumstance of constructional measures of seismic intensity VII through an earthquake shake table test on a model of a six-story reinforced masonry structure with small-sized concrete hollow blocks. In view of the whole test process, the integral deformation of the reinforced masonry structural model under the influence of seismic vibration is predominantly bending deformation. While inputting different earthquake intensity, the transverse peak average of maximum input acceleration that can be sustained by the structure is lower than that of the vertical peak average. Meanwhile, transverse deformation is more severe than vertical deformation, indicating that vertical seismic resistance capacity is stronger than transverse seismic capacity. The test result shows that the effect of the constraint system consisted of ring beam, constructional column as well as horizontal tie reinforcement is quite obvious, the structure possesses comparatively strong resistance of failure under the influence of moderate and strong earthquakes, which can completely meet the requirement specified in the Seismic Codes, that is, standing erectly when it is subjected to great earthquakes in the area of seismic intensity VII. When the structure is subjected to rare earthquakes, it also possesses considerable seismic resistance capacity.

Abstract: Isolation technique has been acceded as a part of the China Seismic Code for Design of Buildings. In this code, the limitations for using isolation design are very strict, superstructure must be regular and the isolation layer must be located on the top of base (base isolated structure). Because of the needs of architecture and function or the feasibility of technique, some limitations have been broken in recent projects. Sometimes isolated layer can be set on the intermediate story, so-called the mid-story isolated structure. According to the characteristic of structure, isolation layer of mid-story isolated structure is set on a place where the structure’s vertical stiffness is suddenly changed, as like the top of the first story, middle story, conversion story of the structure. Laminated rubber bearings (LRB) are adopted as an isolation layer. Because the isolation layer is set on intermediate story, the whole structure is divided into superstructure and substructure; the structure’s dynamic characteristics are changed. The mechanism of mid-story isolated structure appears different characteristic compared with base isolation. The aim of mid-story isolation is not only to reduce seismic responses of superstructure, but also to reduce seismic responses of the substructure. Theoretical analysis and the shaking table test of the mid-story isolated structure were carried. And the response of mid-story isolated structure is discussed by comparing with the response of base-isolated structure and base fixed structure. The key problems of mid-story isolated structure are the force condition and the interaction of the structure up and below the isolation layer. Many factors, such as the number of story, mass, stiffness of superstructure and substructure, parameter of the isolation layer, have influence on the seismic behavior of the mid-story isolated structure. The optimum combination relationship of these factors is presented and dynamic characteristics and dynamic responses are investigated.