Abstract: Within construction industry developing rapidly in domestic, long span buildings and high-rise buildings emerge in endlessly. Steel tubular structures are increasingly widely used for its unique advantages. Thanks to the situation, flange-plate connections become more and more popular as an important solution of splicing steel tubular structures. The connections provide easy and fast installation，nice shape, simple constitution for tubular structures without the need for welding. Typical loading situations include axial tension force and moment for flange-plate connections. The loading capacity under axial tension was studied by many scholars. Unfortunately, study on flexural capacity of flange-plate connections is limited. This situation limits the generalization of the nice connections. As can be seen from the review on flange-plate connections, there is no doubt that doing research on flexural capacity of flange-plate connections is necessary. Previous studies on axial loading capacity of flange-plate connections can provide helpful options of research for this work. One of the options is to observe the prying forces caused by flange-plates’ deformation, for prying is an important influencing factor on axial loading capacity of flange-plate connections which can reduce capacity of the connection. It is same as axial loading case that prying forces exists in the tensile region of flange-plate connections under bending moment, and they should be paid attention because they can reduce the flexural capacity of the connections with no doubt. This paper addresses on four basic kinds of flange-plate connection’s flexural capacity and is developed by means of finite element method with finite element program ANSYS. Related FE models are established and checked compared with experimental results. Based on the reliable FE models, the subsequent analysis especially studies on the effect factors of prying force in the tensile region of connection in the tensile region of connection. The corresponding parametric analysis is developed, including the thickness of flange-plate, the ratio of outer and inner diameter of flange-plate, material property of bolts, etc. Finally the key effect factors are found. The conclusions from this paper can provide references for Engineering Design.
Abstract: Abstract. In the presented paper, reverse push-out test method was put forward and applied in the ultimate bearing capacity experiments of studs with concrete slab in tension. Ultimate bearing capacity experiments were carried out on 22 reverse push-out specimens composed of C50 or C40 concrete, 14MnNbq steel girder and Φ22studs. Results showed that ultimate bearing capacity of studs, pu, in tensile concrete slab is controlled by concrete failur, concrete strength, studs arragement and reinforcement ratio are the main influence factors of pu. Compared with that in compressive concrete, pu of Φ22 studs in tensile concrete is reduced about 30% averagely. According to the test results, a fitted load-slip relationship curve and a regression formula of pu for studs in tensile concrete were put forward, calculated results were in good agreement with the test results.
Abstract: Development of multi-story and high-rise steel three-dimensional (3D) garages is an effective way to solve the parking problem in modern cities. In this paper, several types of multi-story and high-rise steel 3D garages are presented. The structural configurations and design parameters of the 3D garages, such as structural planar layout, storey height and limit value of horizontal displacement, are analyzed. Then the economic performances of the steel 3D garages are compared and their suitable storey numbers are obtained.
Abstract: The guyed mast structure consists of a vertical shaft supported along its height by several layers of inclined pre-tensioned guys. The central shaft is generally made of lattice steel structure, and the guys are spaced at equal angles around the mast to ensure the vertical shaft’s stability. By taking a 102 m meteorological guyed tower in Hainan as an example, this paper made two design proposals using steel pipe and round steel material for the shaft respectively. According to the requirements of the project, this paper then did non-linear static analysis and buckling analysis of the structure by finite element software SAP2000, and compared the results of the two proposals so as to find the optimal one. The results show that steel pipe material is more economical when used for the mast shaft and more reasonable for bearing forces. The choice of the number and the initial tension of guys, as well as the wind vibration coefficient, which have a great effect on a guyed mast, are also discussed in this paper.
Abstract: The leading building in Magic Cube Time Square in Jiangyin is a rare large-cantilevered structure in China, with the standard floors overhanging 9m outwards. Concrete filled tube columns in large diameter and steel beams are applied in the peripheral part of the building frame. In this research, the full-scale test is conducted to investigate the mechanical performance of the concrete-filled beam-column joint. Self-balanced loading frame with dimensions of 15m×10m×10m is built due to the complexity of the joint, the greatness of load and the difficulty of loading condition. Meanwhile, the finite element model is generated to inspect the performance of the beam-column joint under the test loads for verification. Through comparisons of test results and FEM results, good mechanical performance and reasonable load transfer mechanism of the joint are presented in the paper. It is verified that the joint is reliable under 1.3 times of the design load. The effect of ring stiffeners is also studied in this paper.
Abstract: Used of finite element software, based on the material characteristic and node semi-rigid experimentations, the model with material multi-linear kinematic hardening and node semi-rigid was established to simulate the test model of coupler steel tube falsework. According to the measured data of the defect, to analyze the nonlinear stability of the model by methods of the consistent defect mode and stochastic defect, the results indicate that the model’s correctness and consistent mode imperfection method’s in analyzing coupler steel tube falsework is feasible, and the structure is a defect-sensitive structure. The brittleness failure characteristic of coupler steel tube falsework was validated and several effective conclusions were educed after comparative study on the deformation mode and load-displacement curve of the test, consistent defect mode method and stochastic defect method.
Abstract: The spiral steel stair is widespread used as indoor stair for its graceful appearance. For the space structure system of the spiral stair, it is necessary to make vibration analysis and comfort evaluation to the stair. The load model of pedestrian and the analysis condition by walking and running in the process of ascending and descending are presented in this paper. Referring to some design code and research achievement of footbridge and floor, the index of comfort evaluation, which are the natural frequency, the peak vertical acceleration and the weighted root-mean-square (r.m.s) acceleration, are put forward in this paper. Finally, the numerical analysis and the vibration site test of a practical project are made and the results of vibration analysis and comfortability evaluation are presented to demonstrate the suggestion by the authors.
Abstract: For links in eccentrically braced frames (EBFs), today’s design codes requirement of the flange width-thickness ratio is strict on high-strength steels, which eliminate a number of rolled wide-flange shape from use in EBFs. For this reason, building models using ANSYS program and control procedures for the previous tests to verify the correctness, and then design the specimens. This paper applies unidirectional load and cyclic load on the finite element models respectively. Through the calculation of the inelastic rotation which the link beams reach after the relaxation of the flange width-thickness ratio, the paper analyses the influences on the performance of the three tapes of links by the flange width-thickness ratio.
Abstract: Buckling is often the main design consideration for thin cylindrical shells. For most load cases, the stability behavior of the shell is acutely sensitive to circumferential weld-induced imperfections, and the corresponding residual stresses are some beneficial to buckling strength of the shell generally. However, these conclusions are all based on the cylinders with constant wall thickness, and the studies about the effect of residual stresses on buckling strength of tapered cylindrical shells under partial axial compression are few. This paper applies trapezoidal strain field approach to simulate circumferential weld-induced imperfections on tapered cylindrical shellls, and studies the stability behavior of the cylinders with single circumferential weld and multiple circumferential welds under partial axial compression respectively. By comparing the results derived from the models with/without circumferential welds and corresponding residual stresses, the effects of weld depressions and residual stresses on tapered cylindrical shells under partial axial compression are obtained.