Advanced Materials Research Vols. 368-373

Abstract: In this paper, the middle-span space truss is chosen as the research object, and viscous dampers are introduced into the space truss as damping elements. The method of “fast non-linear analysis (FNA)” is adopted to numerically simulate the dynamic response. The better selection of the layout, number and damping index of dampers is intensively studied. Finally, more economical and practical results of damping design with viscous dampers are achieved, which can provide a reference for the design of the same kind of structure.

Abstract: This study focuses on the reliability assessment of buildings subjected to moderate earthquake loadings. The safety of the buildings is expressed with criteria of both global level and member level summarized from the deformation-based design theories in the overseas codes. The inter-story drift ratio is chosen as the key criteria. An allowable inter-story drift ratio of repairable level is proposed for seismic design, and a numerical example is examined. The results indicate that the allowable inter-story drift can effectively control the damage level under moderate earthquake.

Abstract: Ten construction sites are chosen as survey places, and several parameters for scaffold designing are collected, such as the wall thickness of steel tube, the weight of three kinds of couplers, the working tighten-moment on belts of couplers. Corresponding to different tighten-moment of the right angle coupler and anti-slipping tests are carried out. Reliability of 97% and wall thickness of 2.7mm should be considered in scaffold designing only about 10% of the practical used couplers comply with the National Code. The working tighten-moment of couplers should be 40 ～ 50N • m, which is up to the load bearing capacity of coupler.

Abstract: Against the problem of the aerodynamic interference effects on aerostatic coefficients between parallel continuous rigid frame bridges with high-pier and long-span, the aerodynamic interference effects on aerostatic coefficients of double thin-walled hollow pier in the parallel long-span continuous rigid frame bridges were investigated in details by means of wind tunnel test．The space between the two piers and wind direction angles were changed during the wind tunnel test to study the effects on aerodynamic interferences of aerostatic coefficients of twin piers. The test got aerostatic coefficients of 8 conditions. The research results have shown that the aerodynamic interference effects on aerostatic coefficients of double thin-walled hollow pier in parallel bridges can not be ignored. The aerodynamic interference effects on parallel bridge pier is shown mainly as follows: The tandem interval and wind direction angles are important factors affecting interference effects. The drag coefficient of pier downstream dropped and the drag coefficient of pier upstream changed but Not change significantly. There are also the aerodynamic interference effects of lateral force coefficient and torque coefficient between the piers upstream and downstream. The effects upstream are smaller and the effects downstream are larger.

Abstract: Based on the investigation of vehicle loads, the model of the random dense vehicle load was simulated, and three different degree dense vehicle loads were obtained with the simulated model. The calculated results show that the random dense vehicle loads moving on the bridge structures is very dangerous for the security of the structures.

Abstract: This study focus on derivation of such fragility curves using conventional old reinforced concrete (RC) frames with Mild Steel Damper (MSD) of flexural energy dissipation braces. A set of stochastic earthquake waves compatible with the response spectrum of China seismic code selected to represent the variability in ground motion. Dynamic inelastic time history analysis was used to analyze the random sample of structures. Weak position was be pointed out, The result reveal that excellent reduction effect for structure of MSD is favorable and obvious under major earthquake.

Abstract: In order to control the safety of R.C structure, the construction loads of multistory frame reinforced concrete buildings in xi’an were selected as the research objective. Based on the characteristic of construction loads, the survey on the work site had carried on during the construction progress. Variation of concrete dead weight had been discussed. And the mathematics models of live loads in different stages of construction process for reinforced concrete buildings were proposed through statistic analysis. The standard values of construction live loads were suggested at last.

Abstract: This paper analyses the characteristics of resistance of structural components, puts forward the concept of early resistance force of structural components, and discuss the main factors which affect it based on the field measurement investigation and theoretical analysis. Besides, in the paper the reduction factor is applied to reflect time-varying features of early-age concrete strength, and utilization coefficient of concrete strength is utilized to present the influence of early time-varying features of cohesive action on resistance. The paper finally deduces the formula of early-age resistance force of typical flexural member, and gives the time-changing law of early resistance by using a case.

Abstract: In this paper, the large-scale finite element software ABAQUS is used to study seismic behavior of T-shaped concrete-filled steel tube compound columns with different axial compression ratios. We determine the appropriate type of unit, measure off rational mesh, choose rational algorithm, through this simulation analysis. And we can get the hysteresis curves and skeleton curves of the columns with dies and management. The destruction and the deformation pattern of the whole columns can be seen different axial compression rations. The results show that the difference of axial compression rations has great impact on seismic behavior of T-shaped concrete-filled steel tube compound column.

Abstract: This paper investigates the interlaminar stress distributions at hole edge of notched thermoplastic laminates. Two numerical models of AS4/PEEK laminates with configuration of [±25]_S4 and [0/±45/90]_2S were built and studied by finite element code ANSYS. The results show: (1) The angle-ply configuration ([±25]_S4) may cause more severe concentration of interlaminar shear stress at hole edge; (2) the quasi-isotropic configuration ([0/±45/90]_2S) can lessen the stress concentration at hole edge.