Effect of the Thick-Walled Steel Tubular Joint Stiffness on the Overall Stability of a Single-Layer Latticed Shell

2014 ◽  
Vol 501-504 ◽  
pp. 791-795
Author(s):  
Lan Chen ◽  
Bo Yin

As a new type of joint, the thick-walled steel tubular joint is applied in the single-layer latticed shell to solve the connectivity problem of rectangular tube. In combination with the design of practical project, the effect of the new joint stiffness on the overall stability of a single-layer latticed shell and the value of joint stiffness are studied by ANSYS. Some parameters as the rectangular tube section, the thickness of thick-walled steel tube and connecting plate are taken into account in the process of geometric nonlinear analysis. The results show that joint stiffness has great influence on the overall stability of a single-layer latticed shell and the range of effect gradually increases with the growth of rectangular tube section.

2010 ◽  
Vol 163-167 ◽  
pp. 137-142
Author(s):  
Fan Wang ◽  
Zhi Gang Zhang ◽  
Min Luo

This paper focuses on the research of stability capacity of shells with openings, the judgment of joint rigidity and the influence of joint rigidity on stability capacity of shell structure. The research result showed that it should give priority to use ribbed-Schwedler shells for the shells with large openings. Currently, there is no clear standard for judging joint rigidity, this paper presents a way to identify the steel joints stiffness. In the structural design of Chang'an stadium, according to the joint structure, it is proved to be hinged node by analyzing the joint stiffness. Buckling analysis results show that: single-layer shell with hinged nodes also has good stability. The result of the research has a certain value to practical engineering design.


2014 ◽  
Vol 1078 ◽  
pp. 220-223
Author(s):  
Wen Bin Shi

ANSYS14.0 structural analysis software is used in order to make a ring rib-reticulated shell for the overall stability analysis. Considering the geometric nonlinear analysis and initial geometric imperfections influence , obtain a key node of the load - displacement curve and assess the ultimate strength of the structure. The results showed that: the structure meets the "Space grid rules" for monolayer shells stability requirements. And it is found that load distribution form and initial geometry defect has a great deal whit bearing capacity of single-layer lattice shell stability by comparison.


2021 ◽  
pp. 136943322110073
Author(s):  
Yu Cheng ◽  
Yuanlong Yang ◽  
Binyang Li ◽  
Jiepeng Liu

To investigate the seismic behavior of joint between special-shaped concrete-filled steel tubular (CFST) column and H-section steel beam, a pseudo-static test was carried out on five specimens with scale ratio of 1:2. The investigated factors include stiffening types of steel tube (multi-cell and tensile bar) and connection types (exterior diaphragm and vertical rib). The failure modes, hysteresis curves, skeleton curves, stress distribution, and joint shear deformation of specimens were analyzed to investigate the seismic behaviors of joints. The test results showed the connections of exterior diaphragm and vertical rib have good seismic behavior and can be identified as rigid joint in the frames with bracing system according to Eurocode 3. The joint of special-shaped column with tensile bars have better seismic performance by using through vertical rib connection. Furthermore, a finite element model was established and a parametric analysis with the finite element model was conducted to investigate the influences of following parameters on the joint stiffness: width-to-thickness ratio of column steel tube, beam-to-column linear stiffness ratio, vertical rib dimensions, and axial load ratio of column. Lastly, preliminary design suggestions were proposed.


2013 ◽  
Vol 351-352 ◽  
pp. 1057-1060 ◽  
Author(s):  
Xi Yun Dai ◽  
Xiang Yun Kong ◽  
Lin Tian

Suspend-dome structure form which colligates advantages of cable dome and reticulated shell is a new type spatial hybrid structure system. This article introduced the configuration and principle of suspend-dome structure system, and researched the structural behavior influence by altering the joint stiffness, vector height of the suspend-dome and the loop cable pretension. The results show that suspend-dome structure should make comprehensive consideration on interaction between vector height, prestress application and other factors, and relevant optimizing design method can be adopted in the design.


2011 ◽  
Vol 255-260 ◽  
pp. 1198-1203 ◽  
Author(s):  
Ye Sheng

The weakness of traditional dumbbell-shaped section is that when concrete is filled into the web space, great stress is likely to produce cracks in the weld sealing between steel tube and web plates. In order to avoid this condition, a new-type dumbbell-shaped section is proposed. Experiments on concrete filled steel tubular (CFST) model arches with new-type dumbbell-shaped section have been carried out, concentrated loading at crown and L/4 section respectively. The result indicated that the new-type CFST arch has good elastic-plastic behavior and high strength, no local buckling appeared during the whole loading process, its in-plane mechanic behavior is similar with that of the CFST arch with single-tube. The dual nonlinear finite element calculation model is set up for the model arch, by means of this model the load-deflection curves during the loading process and the ultimate load-carrying capacity is analyzed.


2012 ◽  
Vol 166-169 ◽  
pp. 3277-3281
Author(s):  
Min Tong

Abstract. Connection joint with penetrated diaphragm, which is better for the stressing state of the welding connection, is a new type joint for the beam and column connection. Static test and pseudo-static test are put to 17 crossing joints. The stress distribution of the steel beam and the penetrated diaphragm are discussed. The experiment shows that the penetrated diaphragm transfer most tension force of the steel beam’s upper flange to the core region of the joint, which could effectively decrease the stress and strain gradient within the connection area of the steel beam’s upper flange and steel tube column. As the result, the shear force of the core region is decreased. The front weld is avoided being surfing great tension. The ductility of the joint and the energy dissipation capacity of the structure are then increased. The type and the size of the penetrated diaphragm show great affection to the stress distribution of steel beam and penetrated diaphragm. The study achievement enriches the joint connection type of the composite structure with concrete- filled steel tube.


2018 ◽  
Vol 38 (2) ◽  
pp. 242-252
Author(s):  
Jianrong Yang ◽  
Zhiyu Zhang

A new concept of a flexible rock-shed is presented for protection of the railway from falling rocks. The flexible rock-shed is made of flexible nets connected by specific spring spacer bars to an array of reinforced concrete portable frames which are linked by a longitudinal steel tube truss. To evaluate the performance of the flexible rock-shed, experimental and numerical studies are carried out in the present study. Impact tests are conducted on a full-scale partial model of the prototype structure when it is subjected to a falling block of 340 kg. The impact time interval, maximum deflection of the flexible net, tensile forces in the supporting ropes, and axial strains of spring spacer bars are recorded. To further examine the dynamic behavior of the flexible rock-shed, numerical simulations are also carried out by using the explicit finite element code ANSYS/LS-DYNA. It is found that the numerical results coincide well with the experimental data and both the numerical and experimental studies reveal that the structure can withstand impact energy of 50 kJ with all the materials working in the elastic range. The structural details are improved and the basis for the design and construction of similar structures in the future is provided.<br>


2019 ◽  
pp. 139-145
Author(s):  
A. N. Mikhailov

A new type of single‑layer transrefleсtor structure based on microstrip reflective antenna array is described. The developed  device is a single‑layer printed circuit board on one side of which a system of printed reflectors is located, and on the other is  a polarization structure consisting of parallel metal conductors, in contrast to a microstrip reflectarray antenna. The shape and  geometrical dimensions of printed reflectors arranged in a rectangular or hexagonal (triangular) pattern are chosen in such a way  that they transform a spherical front of an incident vertically polarized electromagnetic wave into a flat front of reflected wave. In  the case of irradiation of the developed transreflector with a horizontal polarization wave, the printed structure makes minimal  electromagnetic energy loss during its passage. The results of characteristics modeling (including phase curves) of an element  of the reflective lattice in the W‑band for different angles of incidence of the wave on the planar structure under study are given.  Based on the results obtained, the sizes of the reflective elements of the transreflector, which provide for the correction of the  incident wave with the necessary phase discrete, are determined and an electrodynamic model of the transreflector antenna is  built. The simulation of the main radiation characteristics of the antenna with the developed single‑layer transreflector was carried  out.


2018 ◽  
Vol 42 (2) ◽  
pp. 187-193 ◽  
Author(s):  
Jingwen Xu ◽  
Yunxuan Zhang ◽  
Ziqi Yin

In this paper, an extreme learning machine (ELM) network based on an improved shuffled frog leaping algorithm (CCSFLA) is applied in early bearing fault diagnosis. ELM is a new type of single layer forward network. Although the generalization is stronger compared with traditional neural networks, a random setup of initial parameters increases instability of the network. An improved SFLA based on sinusoidal chaotic mapping with infinite collapses and constriction factors (CCSFLA) is proposed in this paper to optimize the ELM and obtain a CCSFLA–ELM model. Results show that the CCSFLA–ELM model can be used for optimization and that it improved the recognition of early bearing fault diagnosis.


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