Abstract: The unique features offered by wireless smart sensor networks (WSSN), including high integration, wireless communication, on-board computation, small in size, simple installation, and cost effectiveness, facilitate a new paradigm to structural health monitoring (SHM) for civil infrastructure. The paper is an example use of WSSN and the Illinois SHM Project toolsuite. An experimental study of modal analysis of a simply supported plate structure has been undertaken. The eigensystem realization algorithm (ERA) in conjunction with natural excitation technique (NExT) and stabilization diagram (SD) is used to extract the modal information, including natural frequency, damping ratio and mode shapes, from the ambient vibration test data. The results show that WSSN designed for SHM application utilizing a smart sensor platform suited to high-frequency, high-fidelity data acquisition and demanding data processing algorithms.
Abstract: Due to the increasing of wind disaster, structural wind engineering arouses more and more attention recently, with rapid development on spatial structure and continuous innovation of structural style. The main purpose of structural wind engineering is to calculate the wind pressure coefficients of structure. In this paper, the numerical wind tunnel method (NWTM), based on the Computational Fluid Dynamics (CFD), is applied to study wind load. The wind pressure coefficients of reticulated spherical shell with the 4.6m high wall were first determined, using the NWTM. The results are then compared with the wind tunnel test (WTT) and good agreement is found. The feasibility and reliability of NWTM were then verified. As the second example, NWTM is carried out to predict wind-induced pressure on reticulated spherical shell without wall. Further the distribution behavior of wind pressures on this kind of structures is discussed which could provide professionals the reference for the design of structure.
Abstract: The experiment system of a three-floor reinforced concrete frame-shear wall eccentric structure has been built based on Matlab/Simulink software environment and hardware/software resources of dSPACE. And then a shaking table test for the hosting structure with and without magnetorheological (MR) dampers is implemented subjected to three different ground motions. The FBG strain sensors were used in this experiment for strains measurement of the columns and monitoring of the appearing and developing of cracks under different stages. The experimental results show that the control strategies of MR dampers have significant effect on axial force of the column.
Abstract: The Paper reviews the mechanism and structure performance of reinforced concrete members strengthened with bonded steel sheets. It enriches the concept of restrained area of bonded steel sheets and method of design of these kind of members based on enormous experiences.
Abstract: The modified Levenberg-Marquardt (mLM) method is introduced for nonlinear parametric system, such as stiffness proportional damping and Rayleigh proportional damping. Since the mLM method is sensitive to the initial values of parameter, a SVD-mLM method is proposed with combination of singular value decomposition (SVD). Parameter identification of five-storey shear-type is simulated with incomplete output. The results show that the identified parameters have high precision, and the proposed method is effective and robust on noise.
Abstract: In this study, the procedure of Pushover analysis has been put into effect, and following factors have been mainly researched in Pushover analysis: choosing the calculation model of structure and element; analyzing the yielding moment and limiting moment of cross section; posing the distribution pattern of lateral force; discussing the influence of high class mode of vibration on the structure. The following conclusions are given by analyzing a frame damaged by the seismic load with the help of the ANSYS software.
Abstract: In this study, a Buoyancy Preflex Method was introduced to enhance structural safety and performances for a large floating structure on which recently many studies are actively conducted worldwide. To demonstrate the effect of the Buoyancy Preflex introduced to the floating structure, an analytical study was conducted using parameters such as the ratio of the lengths of center modules to those of end modules. The analysis models for parameter were modeled into 5 cases, then a hydrostatic analysis on live load was selected from Equivalent Static analysis methods, then was conducted. The analysis procedure was divided into two steps, before and after live loading. As The result of this study, first analysis step, it was confirmed by each analysis model that excellent buoyancy preflexes were introduced. Even after the live loading, the 2nd analysis step, compressive stresses occurred at the bottom slabs of all analysis models, which enabled a determination that all analysis models can afford to secure safety and structural performance against live load.
Abstract: In view of the universal present situation where general rural buildings has low earthquake resistance ability, this paper, based on the base Isolation theory and the steel-asphalt isolation layer, proposes the steel-asphalt isolation pier to overcome the shortcomings of relatively complex construction and inconvenient volume production. The present study has also carried full-scale model experiment on the houses of single-layer full-scale masonry structure. The result shows that with the sine wave input of different acceleration amplitude, the superstructure acceleration weakens more than 40% and gets good damping effect because a majority of seismic energy has been absorbed by the isolation pier; and when the acceleration amplitude is below 0.30 grams, the steel of isolation pier is to be at the elastic state and can reset automatically after shock, which can satisfy the requirements of the seismic design. However, in order to meet the demand of the topic research, the present study has only done experiment on the small earthquake. According to the research findings, the attenuation coefficient , on the whole, tend to increase with the increase of acceleration peak value.
Abstract: The paper makes a reliability analysis of composite space truss based on integral loading ultimate state. Double nonlinear numerical model is established based on finite element software ANSYS to track the ultimate loading capacity of the structure and confirm the failure mode of the structure; by the deep research and discussion for the composite space truss based on integral loading ultimate state, the scope of structural reliability index and sensitivity degree of various parameters to the reliability are obtained and the measures for improving reliability are proposed.
Abstract: According to good property of concrete-filled steel tubes(CFST) when they are subjected to compression load and their disadvantage to bending load. A new type of composite external prestressed concrete-filled steel tubular structure has been presented in this paper, which has the high tension strength of prestressed tendon and good anti-compression capacity of CFST. Based on the analysis of the mechanism, the flexural capacity of the structure can be greatly enhanced. And the criterion and method is given.