Applied Mechanics and Materials Vols. 226-228

Abstract: Radiant cable suspendome based on single-layer lattice shell is proposed in this paper whose cable-strut system is like that of Radiant Beam String Structure, the purpose of this paper is to do stability analysis of the structure.The linear buckling analysis of the hybrid structure and the single-layer lattice shell who has the same geometry parameters is carried out, we can preliminarily understand the stability of the hybrid structure. At the same time, nonlinear buckling analysis is carried out to study the stability of the hybrid structure under different rise-span ratios, different prestress level and half-span load. The results show that the introduction of prestressed cables greatly improve the structure's stability and reduce the structure sensitivity to original geometrical imperfection.

Abstract: Quasi-static analysis is of a simulation of static problem with motion analysis which restricting the load velocity so that the outcome we got can only have a little inertia influence which we can neglect. In order to solving stability problem of stiffened plate under axial pressure, we adopt this quasi-static analysis which applying displacement on structure. In pro-buckling, compared to the static analysis, quasi-static analysis can get the structure responses accurately with less time cost; In post-buckling, quasi-static analysis can get the structure responses which static analysis can’t get. With this we provide a new method in static problem

Abstract: Based on the component method of EuroCode3, a new component model to evaluate rotational properties of extended end-plate beam-to-column joints under shearing and bending loads has been proposed in this paper. Firstly, the T-stub model was set up. And then the end-plate beam-to-column joint was simplified with a set of T-stubs. Finally the end-plate beam-to-column joint was simulated by the proposed component model consists of a series of levers and equivalent springs. With the purpose of verifying and calibrating the proposed model, an experiment of extended end-plate joint is recommended and a corresponding finite element model has also been set up. Results of experiment, FEM and component model fit well each other. The method of this paper can describe the rotational property of end-plate joint under beading moment and shear with enough precision, which can be a useful improvement to conventional design codes.

Abstract: In conventional analysis and design, the beam-column connections are divided into two categories: fully rigid joints and perfectly pinned joints. Actually, most beam-column connections exhibit flexibility. Idealized connections may diverge from the real reaction of structures. This article presents a hybrid finite-element model that consists of a beam element with two semi-rigid connections at the ends for studying the effect of the flexibility on the structures. Based on the theory of finite deformation, the first-order and the second-order stiffness matrix and the equilibrium equation of hybrid beam element were got. A nonlinear finite element analysis program was developed to analysis the steel frames with semi-rigid connections. At last, one-bay, two-story semi-rigid planar steel frame was analyzed using the program, and some conclusions about the effect of semi-rigid connections flexibility were obtained.

Abstract: Shanghai Expo Puxi Entertainment Hall is reconstructed based on existing workshop building. To meet new function requirements of the hall, a structural column is removed and replaced with a jacking beam. A structural safety monitoring system is proposed and applied to evaluate the real-time structural state and ensure the structural safety. Vibrating wire sensors and FBG sensors are installed to monitor the stress of member of the space truss structure; ForesightTM series DSTS (Distributed Strain and Temperature Sensors) is installed to monitor the stress of the jacking beam. Results show that the structural safety monitoring system works stably. The safety monitoring system reflects the real-time behavior of the structure and controls the structural reconstruction safety effectively.

Abstract: The construction process of the large span spatial steel structure was studied by finite element method and the time-varying mechanics. The construction process of complex spatial frame structure was divided into the installation and dismount supporting phase, and each stage was divided into 15 steps in which mainly simulated and analyzed the whole construction process by "life-death" element. The critical control points of each construction step were identified, the stress state, interval value and the maximum stress in the structure of each construction condition were conformed; rod deformation in construction process was analyzed in construction program. The result showed that the large span spatial steel structure construction scheme was numerical simulated and calculated by the method of finite element analysis and the mechanical state, deformation and safety of building structure were predicted accurately during construction.

Abstract: Based on the statistical probability of abnormal frequency offset, this paper puts forward a new structural damage alarm index. Demonstrating the feasibility of corresponding structural damage alarming method, this article introduces the index to analize a steel frame structure in frequency domain. The results show the abnormal index defined in sense of statistics indicates the abnormity of corresponding test cases clearly.

Abstract: The tuned liquid damper (TLD) is a proven and an increasingly popular auxiliary device for mitigating the dynamic effects induced by wind loading on tall buildings. As buildings become taller, lighter, and more flexible, there is a greater contribution from the dynamic component. The most reliable tool for assessing the dynamic component is wind tunnel testing. A boundary layer wind tunnel is capable of accurately calculating an equivalent static wind load (ESWL) acting on a building. The current study investigates the reduction in the ESWL of a lateral-torsional coupled building with a TLD system installed. The building is sensitive to torsion in the first two vibration modes. The current investigation uses three unique multi-modal TLD systems designed specifically for a lateral-torsional coupled building. The building ESWL is evaluated with the TLD systems using measurements from tests conducted at the Boundary Layer Wind Tunnel Laboratory at Western University.

Abstract: In order to provide reference data for the safe construction and validation of the design method is correct, the subsidence monitoring for tall buildings (high-rise structures) which are being in the construction or completed. In this paper according to the actual settlement monitoring data, on basis of considering the construction stage, the settlement data were segmented regression analysis. The results show that in stage of load (in construction) uniform increasing, the settlement and load a linear regression analysis results are better than the results of settlement with time linear regression analysis, While in the building after the completion, the settlement with time were the logarithm function regression analysis, hyperbolic regression analysis and power function regression analysis. The regression analysis results show that hyperbola regression analysis method is of minimum variance and the regression analysis effect is best, the final settlement value was predicted and providing reference basis for construction and design.

Abstract: The stability bearing capacity of axially compressive loaded fixed-ended channels with complex edge stiffeners were analyzed by direct strength method in this paper. A total of 292 examples with different parameters were selected to be studied by nonlinear finite element analysis. As the members with fix-ends, the failure modes include local and flexural-torsional interactive buckling, distortional and flexural-torsional interactive buckling. The revised direct strength method was put forward. After revise, the formula is in good agreement with experimental results. It is shown that direct strength method is valid for predicting the stability capacity of axially loaded fixed-ended channel columns with complex edge stiffeners. We suggest using the DSM3 to calculate the cold-formed thin-walled steel fixed-ended channels with complex edge stiffeners under axial compressive load.