Applied Mechanics and Materials Vols. 256-259

Abstract: The damage criteria of steel frame structure for fiber level, member level and story level are proposed. The fiber level damage criteria is directly defined by the developed steel damage model, the damage criteria of steel member is averaged through all the fibers of the member, and the story level, the damage criteria is defined as the weighted average value of the members, which the weighting factor is defined as the first several relative frequencies increase of residual structure after the evaluated member was demolished. As a numerical example, the damage process of a 9-story benchmark steel frame is analyzed through IDA (Incremental Dynamic Analysis) method in term of structural global damage index, and the damage distribution of each story is proposed as well.

Abstract: Double inner and outer latticed shell string structure is a new type of space structure. The new structural system is to reduce the space occupied by roof structure and could be laid by the rigid roofing material conveniently. Based on the local analysis method and the whole system balance, a numerical algorithm was introduced and some suggestions for improvement were put forward. An example was investigated and the results confirmed the feasibility of the proposed method.

Abstract: Through the ultimate bearing capacity test of 2 prestressed concrete T-beams, the cracking load, the failure load, the control section stress, and the crack and deformation were tested respectively. The mechanical behavior differences of retard-bonded prestressed concrete between T-beam and ordinary prestressed concrete T-beam were contrasted. The test results show that: the change rule of the measured value of deflection and strain is basically the same between the retard-bonded prestressed concrete T-beam and the ordinary prestressed concrete T-beam. Compared with the measured value of the ordinary prestressed concrete T-beam, the cracking load of retard-bonded prestressed concrete T-beams is 10% greater, the failure load of retard-bonded prestressed concrete T-beam is 3% greater. when loading is 80kN, the midspan deflection of retard-bonded prestressed concrete T-beam is 1% greater, when loading is 229kN, the midspan deflection of retard-bonded prestressed concrete T-beam is 2% greater, when loading is 225kN, the crack width of retard-bonded prestressed concrete T-beam is 2% smaller. The average crack spacing of retard-bonded prestressed concrete T-beam is 6% smaller. The retard-bonded prestressed concrete T-beam have better mechanical behavior.

Abstract: Steel and concrete composite beam is a kind of composite beam which the steel and the concrete are connected by shear connectors. Now, many experts and scholars have carried out many experimental research and theoretical analysis about it. But, steel and concrete composite beams strengthened with prestressed FRP bars have not been studied. Based on the structure, the nonlinear analysis mode of steel and concrete composite beams strengthened with prestressed FRP bars is proposed, the calculating program is researched. The relationships between moment and curvature, also between load and deformation of steel and concrete composite beams strengthened with prestressed FRP bars are obtained. The results show that the moment-curvature curve and load-deformation curve of steel and concrete composite beams strengthened with prestressed FRP bars can be separated to elastic stage, elastic-plastic stage and plastic stage.

Abstract: A comprehensive experimental program has been underway at the Structures Laboratory of the University of Adelaide to investigate the behavior of concrete-filled fiber-reinforced polymer (FRP) tubes (CFFTs) under concentric compression. This paper presents the results from a group of selected circular CFFTs and discusses the influence of the critical column parameters on the compressive behavior of CFFTs. These parameters include: concrete strength, amount and type of FRP tube material, manufacturing method of the tubes, and size of the CFFTs. Results indicate that concrete strength and the amount and type of tube material significantly affect the behavior of CFFTs. The manufacture method of FRP tube also has some, but less significant, influence on the behavior of CFFTs. The influence of specimen size has been found to be small. No apparent difference has been found between the compressive behaviors of circular CFFTs and companion FRP-wrapped cylinders.

Abstract: The conference center of the original structure of the frame structure, the ground floors.Now transform the functional requirements to construction, pumping column to the top of the structure to form a large space,Causing the vertical elements intermittent floors stiffness mutation irregular structure system.The basis for reinforced superstructure using SATWE conducted a multi-case earthquake under Elastic Compute using SAP elastoplastic analysis for validation.The analysis results show that the irregular structure, when reasonable structural arrangement, to take appropriate structural measures, the seismic performance to meet the regulatory requirements.

Abstract: Open ended cantilevered roof is different from enclosed roof, because its change of wind pressure distribution is complex, and the wind directions have great influence on it. Up to now, for the characteristics of the structure are very complicated, there is no appropriate wind load model can be used in design, especially under typhoon, a specific wind field. So it is necessary to study the characteristics of wind load on open ended cantilevered roofs of typhoon. Using FLUENT and Computational Fluid Dynamics technology, based on the conventional, Tianpu’s and Shiyuan’s turbulence intensity of the typhoon scenario, a numerical simulation of wind flow around a large-span cantilevered roof was carried out. Analyzed different wind angles of the wind pressure distribution regularities on large-span cantilevered roof. The paper determined the distribution of the surface wind pressure coefficient for the cantilevered roofs, as well as the wind-sensitive parts of structures.

Abstract: Based on the 3D finite element model of the wind power tower, buckling behavior of the wind power tower in different wind directions is analyzed, and the effect considering geometry nonlinearity and considering the material and geometry nonlinearity to the buckling analysis is studied. The results show when the ratio of the radius of the tower drum and the length of the element is 18.75, the calculated precision can reach 95%. Local buckling of the wind power tower first appears, and buckling load and displacement considering the material and geometric nonlinearity reduce 52% and 58% compared with that only considering geometry nonlinearity. The linear and nonlinear buckling load of the wind power tower which is 90° sidewind are 1.8 and 1.2 times than those facing the wind direction.

Abstract: Based on the previous test, SHCC (Strain Hardening Cementitious Composite) with the best fluidity was got through flow test, the different stress-strain full curves of SHCC were obtained by uniaxial tensile test on three dumbbell-shape specimens of SHCC with each group according to different diameter sand and different ages; and crack development was observed during test. The experimental results show that: The finer the sand sizes, the better the strain-hardening performance and more microcrack of SHCC that can be obtained; obvious strain-hardening characteristics of the specimens at different ages are all occured and the ultimate tensile strain can reach or even more than 3%. The crack spacing of various specimens are different, that is to say, there is difference in cracking characteristics among specimens at different ages. The experimental and analytical conclusion can provide a lot of theoretical bases for the research on performances of SHCC.

Abstract: In the design and calculation of staggered steel truss structure, we always assume that truss chord and pillars is hinged while longitudinal beam and pillars is rigid-jointed. But each connection mode in engineering has certain rotary stiffness, they can't completely meet the design requirements. In this paper, 8 finite element models are established with different connection stiffness to compare the effects to the structure performance. In order to explore how the node connection stiffness influence the multi-layers staggered steel truss structure stress on the performance of the law, this paper provide the theory basis for the structure design and construction research.