Abstract: In this paper,a two-way winding-beam space-harmonic excitation beam string under the action of the dynamic response has been studied to capture the dynamic response of the structure of the law, identify the structure of the weak components,and for the design and construction to provide the necessary theoretical data. Using ANSYS finite element software to numerical analysis and reduced scale quarter ratio of model test research methodology to study,using experimental test results and finite element numerical analysis of mutual authentication.Numerical analysis taking into account the geometric non-linear structure,carried out static analysis,modal analysis,harmonic analysis and transient response time-history analysis. Experimental studies of the dynamic signal acquisition and analysis and processing, through the comparative analysis of data, master of the winding space for a two-way steel beam string dynamic response law obtained structural response of the frequency response range,weak location and distribution of components of type of structural design and construction process were proposed.
Abstract: Proposed in this study is a type of friction damper characterized a continuously variable post-sliding stiffness, which provides an increasing post-sliding force with the accretion of the deformation. It is possible to adjust the output force according to the performance targets at different earthquake levels, thus enlightening a practical approach to the explicit structure control to satisfy all of the required performance objectives. Theoretical analyses reveal that the parabola shape of the sliding surface would introduce a cubic force-displacement relationship, which was also demonstrated by sophisticated finite element models. The typical mechanic model was then incorporated into the source code of OpenSEES. The dynamic analysis gave reasonable results and experimental results also demonstrated that the proposed friction damper is able to reduce the displacement response and more important, is helpful to prevent a structure from collapse.
Abstract: Public facilities are the basis of urban public space, and public facilities are core parts of emergency shelters. It is important that the design of rescue facilities focuses on relief efforts. This article analyzes the present situation and raises questions about the study on the design of public facilities in emergency shelters, then applies theory related to design semiotics, cites examples, and suggests improvements on the usability and completeness of public facilities in emergency shelters. Facilities design in emergency shelters provides the theoretical foundation to make rescue system of emergency shelter more effective in the future.
Abstract: Contradiction between thin wall and stability of H-beam is a kind of problem in engineering field, the corrugated web H-beam researched in this paper relieve the contradiction to some extent. This paper apply finite element method of variable section beam and high programming language of MATLAB to analyze buckling strength under axis pressure and effect of critical load of parameter of whole-corrugated web H-beam and contrast to constant cross section H-beam, declaration superiority of whole-corrugated web H-beam with example, supply theory to this kind of H-beam in engineering application.
Abstract: Compared with reinforced concrete shaped columns, bearing capacity and ductility of steel reinforced concrete shaped columns are significantly improved, so it is with theoretical significance and practical application of value to research. Based on the plain cross section presume, with material T-section boundary calculation unit, 15 steel reinforced concrete T-shaped columns(SRCTSC) have made nonlinear full-rang numerical analysis. It demonstrates that the most adverse curvature ductility load angle of SRCCRSC is 180°.Loading angle ( ), axial compression ratio ( ), and the ratio of spacing and diameter of longitudinal reinforcements (s/d) are the principal factors in curvature ductility of SRCTSC subjected to biaxial eccentric compression. It include 36 sets for load angle, 6 sets for axial load ratio, 3 sets for concrete strength, 3 sets for the content of steel, 2 sets for steel style, 3 sets for stirrup ratio, 3 sets for steel location, 3 sets for section size, 3 sets for stirrup diameter about SRCTSC. The ductile behavior of T-shaped, with calculating 1068 loading conditions, are investigated. It concluded that axial load ratio, load angle, and ratio of the spacing of stirrups and longitudinal reinforcement’s diameter (s/d) are most important factors.
Abstract: To study mechanical characteristics of general reinforced concrete in engineering, specimens of reinforced concrete with different mass ratios and specimens of fiber reinforced concrete with different distributing modes of steel fibers or mixed modes of fiberglass are produced. Testing results from these specimens state that recommended mass ratio is 1:4.29:0.74 of cement, sand to water for reinforced concrete, and mass ratio of mixed AR fiberglass is 4‰ or distributing mode of steel fibers is vertical 5 roots evenly for fiber reinforced concretes will have excellent mechanical properties. Analyzing mechanical indexes influencing characteristics of reinforced concretes, uniaxial compressive strength and ultimate strain are primary indexes, elastic modulus is an assistant index, and Poisson ratio and residual strength are both only referenced indexes.
Abstract: To understand mechanical characteristics and seismic behaviors of T-shaped concrete-filled steel tubular (CFST) joints, cyclic loading tests were carried out on four 1/2-scale exterior joints of top floor. The study includes joints’ mechanical character, failure mode, hysteretic behavior, ductility, energy dissipation and stiffness degradation under different height of beam and different axial compression ratios. The results indicate that frame joints satisfy the design principle of stronger joints and weaker components. The hysteretic loops are plump, ductility and energy dissipation capacity is better than that of ordinary reinforced concrete joints. Axial compression ratios can influence seismic behaviors of frame joints to some degree.
Abstract: Corrosion behaviors of low nickel alloy high strength steel (LNAHSS) was studied by electrochemical impedance spectroscopy and scanning electron microscopy when the coupons of LNAHSS were exposed to the seawater culture media. As the results, LNAHSS was uniformly corroded in the fresh sterilized culture medium in a mode of active dissolution; in the culture medium with sulfate-reducing bacteria (SRB), LNAHSS was protected by the iron sulfides layer to some extent in the early stage of exposure, but severely localized corrosion subsequently occurred resulting from the localized breakdown of iron sulfides layer. So, in risks estimation, special precautions should be taken when LNAHSS serves in the environments containing SRB as the localized area can become the tress raiser.
Abstract: The grout sleeve connection offers important complement to traditional steel tube connections and is increasingly applied in structures. To acquire the connection’s behavior under eccentric cyclic load, study and tests were conducted at Tongji University on two specific types of grout sleeve connections which were identical except for some construction measures. The load-strain curve, load-deformation curve, elastic limit bearing capacity and stress-strain distribution of each specimen are obtained as results. Those results indicate that this kind of connection has good bearing capacity and stiffness, and those behaviors can be efficiently improved through optimizing its construction measures.