scholarly journals Seismic analysis method of steel structures connections

2020 ◽  
Vol 17 (2) ◽  
pp. 51-59
Author(s):  
A. I. Garipov ◽  
◽  
P. A. Pyatkin ◽  
Keyword(s):  
Spectral Method ◽  
Seismic Analysis ◽  
Steel Structure ◽  
Steel Structures ◽  
Analysis Method ◽  
Internal Forces

The article presents a technique of calculating steel structures connections taking into consideration the results of seismic analysis of steel structure carried out by linear spectral method. This technique allows reaching the equilibrium of forces and moments applied to the connection, wherein extreme internal forces’ values received correspond to the internal forces’ values obtained according to the currently valid acting construction codes.

scholarly journals Effects of Surrounding Earth on Shell During the Construction of Flexible Bridge Structures

2019 ◽  
Vol 41 (2) ◽  
pp. 67-73
Author(s):  
Czesław Machelski
Keyword(s):  
Steel Structure ◽  
Steel Structures ◽  
Static Condition ◽  
Steel Bridge ◽  
Interfacial Interactions ◽  
Soil Medium ◽  
Bridge Structures ◽  
Internal Forces ◽  
Bearing Loads ◽  
Corrugated Plates

AbstractA characteristic feature of soil-steel structures is that, unlike in typical bridges, the backfill and the carriageway pavement with its foundation play a major role in bearing loads. In the soil-steel structure model, one can distinguish two structural subsystems: the shell made of corrugated plates and the backfill with the pavement layers. The interactions between the subsystems are modelled as interfacial interactions, that is, forces normal and tangent to the surface of the shell. This is a static condition of the consistency of mutual interactions between the surrounding earth and the shell, considering that slip can arise at the interface between the subsystems. This paper presents an algorithm for determining the internal forces in the shell on the basis of the unit strains in the corrugated plates, and subsequently, the interfacial interactions. The effects of loads arising during the construction of a soil-steel bridge when, for example, construction machines drive over the structure, are taken into account in the analysis of the internal forces in the shell and in the surrounding earth. During construction, the forces in the shell are usually many times greater than the ones generated by service loads. Thus, the analytical results presented in this paper provide the basis for predicting the behaviour of the soil medium under operational loads.

Influence of member geometric imperfection on geometrically nonlinear buckling and seismic performance of suspen-dome structures

2014 ◽  
Vol 14 (03) ◽  
pp. 1350070 ◽  
Author(s):  
Z. Zhou ◽  
J. Wu ◽  
S. Meng
Keyword(s):  
Critical Load ◽  
Seismic Performance ◽  
Seismic Analysis ◽  
Great Influence ◽  
Steel Structure ◽  
Analysis Method ◽  
Initial State ◽  
Nonlinear Buckling ◽  
Finite Element Program ◽  
Geometric Imperfection

This paper focuses on the effect of member geometric imperfection on nonlinear geometrically buckling and seismic performance of a new style of space steel structure, suspen-dome, which is composed of a reticulated shell and cable-strut system. By supposing the initial curvature of members as half-wave sinusoids, a stiffness equation of imperfect truss elements is derived for the struts, while that of imperfect beam elements is derived for the reticulated shell members. The proposed imperfect elements are implanted into ANSYS finite element program. Three numerical examples are employed to validate the proposed imperfect elements and analysis method. An ellipsoidal suspen-dome of Changzhou gymnasium is taken as an example. The results show that the imperfection value has relatively great influence on the structural stiffness. With the increase of member imperfection, the critical load decreases in a basically linear way. Under different prestress states, the relation curves between the critical load and imperfection are basically parallel. The nonlinear seismic analysis results show that when imperfection is included, the initial state responses are different, namely, the seismic displacement increases while the stress in rods and cables decreases. The proposed imperfection analysis method can be widely used in not only suspen-dome structures, but also other kinds of prestressed space grid structures. In this way, the influence of member imperfection on structural buckling and seismic performance can be estimated.

Elastic-Plastic Analysis and Research of Large Profiled Structure under Rare Strong Earthquakes Based on FNA Method

2013 ◽  
Vol 838-841 ◽  
pp. 1556-1561
Author(s):  
Na Xie ◽  
Gan Wang ◽  
Jian Zhong Zhao ◽  
Zhi Ming Zhao ◽  
Hui Xin Zhou ◽  
...  
Keyword(s):  
Seismic Design ◽  
Nonlinear Behavior ◽  
Steel Structure ◽  
Steel Structures ◽  
Strong Earthquakes ◽  
Design Goal ◽  
Buckling Behavior ◽  
Plastic Analysis ◽  
Post Buckling ◽  
Internal Forces

In rare strong earthquakes, the steel structure may occur the nonlinear behavior and redistribution of internal forces. In order to understand the post-buckling behavior of steel structures and determine the weak areas of the structure, and then determine whether the structure under strong earthquakes meets the seismic design goal or not, this paper adopts the FNA method to analyze the response of large profiled steel structure under severe earthquakes. Finally, we draw some general conclusions which are valuable for designing the large profiled structure.

Seismic Analysis of Nuclear Project for Joint between Intake Tunnel and Circumfluence Groove

2012 ◽  
Vol 594-597 ◽  
pp. 1219-1225
Author(s):  
Jie Zhao ◽  
Gui Xuan Wang ◽  
Xu Hua Lu
Keyword(s):  
Seismic Analysis ◽  
Time History ◽  
Reference Value ◽  
Internal Force ◽  
Analysis Method ◽  
Load Effect ◽  
History Analysis ◽  
Temperature Load ◽  
Internal Forces ◽  
Dynamic Time

By adopting dynamic time-history analysis method, the seismic analysis for the joint between intake tunnel and circumfluence groove is performed by FLAC3D. Aiming at the mechanical characteristics of this structure and rocky features, according to the design scheme, the analysis of seismic response is carried out, on the base of which envelopes of internal forces are given in this paper. The results show that change of the temperature has much influence on internal force in the same load effect combination. Temperature load also change the direction of internal force in some part. For the similar anti-seismic design, this paper has certain reference value and guiding sense.

Identification and Evaluation of Steel Structure after Fire

2013 ◽  
Vol 438-439 ◽  
pp. 530-534
Author(s):  
Lan Yao ◽  
Yu Min Liu ◽  
Yong Zhi Zou ◽  
Qiao Zhi Lu
Keyword(s):  
Empirical Test ◽  
Steel Structure ◽  
Steel Structures ◽  
Building Assessment ◽  
The Future ◽  
Internal Forces ◽  
Class C ◽  
Engineering Projects

After fire, the strength of steel materials and stiffness of artifacts decrease significantly, which cause the redistribution of internal forces and increase the difficulty in testing of materials, identification and evaluation of steel structures after fire. This paper mainly discusses the identification and evaluation of steel structure of one project undertaken a fire by empirical test. It is speculated that the temperature of the fire was more than 850°C, area covered includes 1~4/Q~W axis and 5~6/H~W axis of the factory, after the fire in the safety appraisal building assessment, it is categorized as class C which influences the safety of the whole structure. From the results of this appraisal, suggestions are made which could be regarded as a guide in similar engineering projects in the future.

Dynamic Characteristics of Base-Isolated Steel Frame under Seismic Ground Motion

2011 ◽  
Vol 255-260 ◽  
pp. 2341-2344
Author(s):  
Mohammad Saeed Masoomi ◽  
Siti Aminah Osman ◽  
Ali Jahanshahi
Keyword(s):  
Ground Motion ◽  
Base Isolation ◽  
Time History ◽  
Steel Structure ◽  
Steel Structures ◽  
Steel Frame ◽  
Nonlinear Time History Analysis ◽  
Seismic Load ◽  
Vector Method ◽  
Seismic Ground Motion

This paper presents the performance of base-isolated steel structures under the seismic load. The main goals of this study are to evaluate the effectiveness of base isolation systems for steel structures against earthquake loads; to verify the modal analysis of steel frame compared with the hand calculation results; and development of a simulating method for base-isolated structure’s responses. Two models were considered in this study, one a steel structure with base-isolated and the other without base-isolated system. The nonlinear time-history analysis of both structures under El Centro 1940 seismic ground motion was used based on finite element method through SAP2000. The mentioned frames were analyzed by Eigenvalue method for linear analysis and Ritz-vector method for nonlinear analysis. Simulation results were presented as time-acceleration graphs for each story, period and frequency of both structures for the first three modes.

scholarly journals Experimental study on fatigue performance of Q420qD high-performance steel cross joint in complex environment

2021 ◽  
Author(s):  
Haigen Cheng ◽  
Cong Hu ◽  
Yong Jiang
Keyword(s):  
Fatigue Life ◽  
High Performance ◽  
Steel Structure ◽  
Steel Structures ◽  
Fatigue Tests ◽  
Fatigue Performance ◽  
Corrosive Media ◽  
Joint Connection ◽  
High Performance Steel ◽  
The Cross

AbstractThe steel structure under the action of alternating load for a long time is prone to fatigue failure and affects the safety of the engineering structure. For steel structures in complex environments such as corrosive media and fires, the remaining fatigue life is more difficult to predict theoretically. To this end, the article carried out fatigue tests on Q420qD high-performance steel cross joints under three different working conditions, established a 95% survival rate $$S{ - }N$$ S - N curves, and analyzed the effects of corrosive media and high fire temperatures on its fatigue performance. And refer to the current specifications to evaluate its fatigue performance. The results show that the fatigue performance of the cross joint connection is reduced under the influence of corrosive medium, and the fatigue performance of the cross joint connection is improved under the high temperature of fire. When the number of cycles is more than 200,000 times, the design curves of EN code, GBJ code, and GB code can better predict the fatigue life of cross joints without treatment, only corrosion treatment, and corrosion and fire treatment, and all have sufficient safety reserve.

scholarly journals A New Approach for Cylindrical Steel Structure Deformation Monitoring by Dense Point Clouds

2021 ◽  
Vol 13 (12) ◽  
pp. 2263
Author(s):  
Dongfeng Jia ◽  
Weiping Zhang ◽  
Yuhao Wang ◽  
Yanping Liu
Keyword(s):  
Steel Structure ◽  
Steel Structures ◽  
Point Clouds ◽  
Deformation Monitoring ◽  
Deformation Analysis ◽  
Relative Deformation ◽  
Structure Deformation ◽  
Single Time ◽  
Cylindrical Steel ◽  
Cylinder Fitting

As fundamental load-bearing parts, the cylindrical steel structures of transmission towers relate to the stability of the main structures in terms of topological relation and performance. Therefore, the periodic monitoring of a cylindrical steel structure is necessary to maintain the safety and stability of existing structures in energy transmission. Most studies on deformation analysis are still focused on the process of identifying discrepancies in the state of a structure by observing it at different times, yet relative deformation analysis based on the data acquired in single time has not been investigated effectively. In this study, the piecewise cylinder fitting method is presented to fit the point clouds collected at a single time to compute the relative inclination of a cylindrical steel structure. The standard deviation is adopted as a measure to evaluate the degree of structure deformation. Meanwhile, the inclination rate of each section is compared with the conventional method on the basis of the piecewise cylinder fitting parameters. The validity and accuracy of the algorithm are verified by real transmission tower point cloud data. Experimental results show that the piecewise cylinder fitting algorithm proposed in this research can meet the accuracy requirements of cylindrical steel structure deformation analysis and has high application value in the field of structure deformation monitoring.

A Framework to Support the Optimization of Modularized Oil and Gas Structures

2018 ◽  
Author(s):  
Vincenzo Castorani ◽  
Paolo Cicconi ◽  
Michele Germani ◽  
Sergio Bondi ◽  
Maria Grazia Marronaro ◽  
...  
Keyword(s):  
Lead Time ◽  
Oil And Gas ◽  
Steel Structure ◽  
Steel Structures ◽  
Modular System ◽  
Test Case ◽  
Plant Design ◽  
Conceptual Study ◽  
A Current ◽  
Gas Plants

Modularization is a current issue in the context of plant design. A modular system aims to reduce lead time and cost in design phases. An oil & gas plant consists of many Engineered-To-Order solutions to be submitted and approved during the negotiation phase. In this context, design tools and methods are necessary to support the design life cycle from the conceptual study to the detailed project. The paper proposes an approach to optimize the design of modularized oil & gas plants with a focus on the related steel structures. A test case shows the configuration workflow applied to a modular steel structure of about 400 tons. The modularized layout has been optimized using genetic algorithms. A Knowledge Base has been described to support the configuration phase related to the conceptual design. Design rules and metrics have been formalized from the analysis of past solutions.

Researches on the Shear Deformation of Joints Domain of Beam-to-Column Connection of Light Steel Structure

2012 ◽  
Vol 256-259 ◽  
pp. 1004-1007
Author(s):  
Xi Bing Hu ◽  
Jian Hua Lu
Keyword(s):  
Finite Element Method ◽  
Shear Deformation ◽  
Design Method ◽  
Steel Structure ◽  
Structure Calculation ◽  
The Finite Element Method ◽  
Mechanics Performance ◽  
Current Design ◽  
Internal Forces ◽  
Complex Parts

The joint domain of beam-to-column connection is very complex parts under loading, which plays an important role in transferring internal forces in light steel structure, such as moment, shear, axial force and so on. Considering the influence of its shear deformation in the structure calculation can help us to reflect the actual mechanics performance and evaluate precisely practical bearing capacity of the structure. According to the actual characteristics of beam-to-column connection, the author established some models of its joint domain, and used the finite element method to analyze and calculate shear deformation of these models. Meanwhile, the author researched the influence of the changes of various parameters to its shear deformation, and provided beneficial suggestions for revising the current design method of light steel structure finally.

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