scholarly journals Reinforcement of steel beam-to-double column moment connection using side plates

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Yousef Zandi ◽  
Afram Keivani
Keyword(s):  
Three Dimensional ◽  
Nonlinear Behavior ◽  
Steel Structures ◽  
Cover Plate ◽  
Moment Frames ◽  
Side Plate ◽  
Panel Zone ◽  
Moment Connection ◽  
The Common ◽  
Three Dimensional Finite Element

One of the disadvantages of conventional steel structures in Iran is the common way of I-shaped beam to double column fixed connection that do not perform well against seismic loads. This article uses the side plate to modify and optimize the connection. Using this new geometry, the beam-to-column direct connection is eliminated, and there is no longer any concern about the brittle fracture of penetration weld of the beam-to-column connection and the weakness of panel zone that occur in the common fixed connections. In addition, by eliminating the direct transfer of beam flange force to the double column connection plate, the problem of deformation, complexity or buckling of the cover plate of the column is spontaneously removed. In this paper, in order to investigate the nonlinear behavior of beam-to-double column connection system, a number of three-dimensional finite element models under the effect of cyclic loading have been analyzed. The results show that the beam-to-double column connection using the side plates has good strength and ductility and can be used in special moment frames for seismic areas.

Application of Fracture Mechanics to Steel Connections in Moment Frames under Seismic Loading

1997 ◽  
Vol 1 (1) ◽  
pp. 23-37 ◽  
Author(s):  
C. Joh ◽  
W.F. Chen
Keyword(s):  
Fracture Mechanics ◽  
Steel Structures ◽  
Northridge Earthquake ◽  
Moment Frames ◽  
Moment Connections ◽  
Related Factors ◽  
Steel Connections ◽  
Moment Connection ◽  
San Fernando ◽  
The Moment

The 6.8 magnitude Northridge earthquake that shook California's San Fernando Valley on January 17 in 1994, did not cause the collapse of any steel structures but connections, confidently designed and constructed in the past with traditional code simplification and common site welding techniques, were discovered not to meet our expectations. This paper reviews connection failures during the 1994 Northridge earthquake and the design philosophy and examines the post-Northridge earthquake experimental and analytical researches. Possible causes of the moment connections damage are categorized into three classes; welding-related factors, design-related factors, and material-related factors. For the analyses, the idealizations of the moment connection considering each factor are studied. From the idealization of the moment connection, the five-plate model is analyzed to investigate the stress concentration and stress state of the connection. The equivalent design crack models are investigated using the fracture mechanics approach.

Structural Stability Evaluation for Lifting Lug Design of Large Marine Engine by Finite Element Analysis

2007 ◽  
Vol 353-358 ◽  
pp. 2855-2859
Author(s):  
W.C. Lee ◽  
Chae Sil Kim ◽  
J.B. Na ◽  
D.H. Lee ◽  
S.Y. Cho ◽  
...  
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Design Procedure ◽  
Steel Structures ◽  
Stability Evaluation ◽  
Element Analysis ◽  
Marine Engines ◽  
Dimensional Finite Element ◽  
The Stability ◽  
Three Dimensional Finite Element

Since most marine engines are generally very huge and heavy, it is required to keep safety from accidents in dealing them. Several types of lifting lugs have been used to assemble hundred ton–large steel structures and carry the assembled engines. Recently a few crashes have been occurred in carrying engines due to breaking down the lugs. Although the stability evaluation of the lifting lug has therefore been very important for safety, systematic design procedure of the lugs, which includes the structural analysis considering stability, has few reported. This paper describes the three dimensional finite element structural modeling for a lifting lug, the studies for determining the reasonable loading and boundary conditions, and the stability evaluation with the results of structural analyses. It should be very helpful for designing the other types of lifting lugs with safety.

scholarly journals Nearby boundaries create eddies near microscopic filter feeders

2009 ◽  
Vol 7 (46) ◽  
pp. 851-862 ◽  
Author(s):  
Rachel E. Pepper ◽  
Marcus Roper ◽  
Sangjin Ryu ◽  
Paul Matsudaira ◽  
Howard A. Stone
Keyword(s):  
Three Dimensional ◽  
Pond Water ◽  
Filter Feeder ◽  
Dimensional Finite Element ◽  
Flow Approximation ◽  
The Common ◽  
Filter Feeders ◽  
Three Dimensional Finite Element ◽  
Approximate Equations ◽  
Good Agreement

We show through calculations, simulations and experiments that the eddies often observed near sessile filter feeders are frequently due to the presence of nearby boundaries. We model the common filter feeder Vorticella , which is approximately 50 µm across and which feeds by removing bacteria from ocean or pond water that it draws towards itself. We use both an analytical stokeslet model and a Brinkman flow approximation that exploits the narrow-gap geometry to predict the size of the eddy caused by two parallel no-slip boundaries that represent the slides between which experimental observations are often made. We also use three-dimensional finite-element simulations to fully solve for the flow around a model Vorticella and analyse the influence of multiple nearby boundaries. Additionally, we track particles around live feeding Vorticella in order to determine the experimental flow field. Our models are in good agreement both with each other and with experiments. We also provide approximate equations to predict the experimental eddy sizes owing to boundaries both for the case of a filter feeder between two slides and for the case of a filter feeder attached to a perpendicular surface between two slides.

Propagation of Buckles in Sandwich Pipes Under External Pressure

2005 ◽  
Author(s):  
I. P. Pasqualino ◽  
M. I. Lourenc¸o ◽  
T. A. Netto
Keyword(s):  
Three Dimensional ◽  
Nonlinear Behavior ◽  
Element Model ◽  
External Pressure ◽  
Core Material ◽  
Small Scale ◽  
Ongoing Research ◽  
Scale Models ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Sandwich pipes have been considered feasible conceptions for ultra deepwater pipelines, since they are capable to work at low temperatures and withstand high hydrostatic pressures. Sandwich pipelines are composed by inner and outer metallic pipes and a suitable core material which must provide high compression strength and good thermal insulation. The aim of this ongoing research is to study the quasi-static propagation of buckles in sandwich pipes. In this paper, a three-dimensional finite element model considering material and geometric nonlinear behavior is presented. The mesh discretization is determined through a detailed mesh sensitivity analysis. Some experiments with small scale models combining aluminum pipes and polypropylene as core material were carried out to calibrate the numerical model. The propagation pressure is evaluated under different bonding conditions between pipe layers.

Applied Research of BIM Technology on Prestressed Steel Structures in Xuzhou Stadium

2013 ◽  
Vol 444-445 ◽  
pp. 971-975
Author(s):  
Zhan Sheng Liu ◽  
Xiao Feng Wu ◽  
Rui Long Xu
Keyword(s):  
Construction Industry ◽  
Three Dimensional ◽  
Steel Structure ◽  
Steel Structures ◽  
Space Structure ◽  
Construction Process ◽  
The Family ◽  
The Common ◽  
Three Dimensional Models ◽  
Prestressed Steel Structure

Prestressed steel structure is the common form of space structure. BIM technology is used to every field of the construction industry. In order to apply BIM technology to the design and construction of prestressed steel structures, Xuzhou stadium prestressed structure was took as an example with BIM technology. Firstly, development standards of the family are created. Secondly, three-dimensional positioning technology and then establishing three-dimensional models of BIM are designed. Finally, the construction process of Xuzhou stadium is dynamically simulated.

scholarly journals Wind-induced collapse analysis of long-span transmission tower–line system considering the member buckling effect

2018 ◽  
Vol 22 (1) ◽  
pp. 30-41 ◽  
Author(s):  
Li Tian ◽  
Haiyang Pan ◽  
Canxing Qiu ◽  
Ruisheng Ma ◽  
Qiqi Yu
Keyword(s):  
Three Dimensional ◽  
Nonlinear Behavior ◽  
Bending Moment ◽  
Element Model ◽  
Collapse Mechanism ◽  
Transmission Tower ◽  
Line System ◽  
Long Span ◽  
Collapse Analysis ◽  
Three Dimensional Finite Element

The collapse problem of transmission tower upon strong winds was well noted in past few years. This article analyses the wind-induced collapse problem of a long-span transmission tower–line system. The member buckling effect was particularly considered. In doing so, a three-dimensional finite element model of the long-span transmission tower–line system was established in ABAQUS based on a practical project. The transmission tower and line were simulated by the frame and truss elements, respectively. The nonlinear behavior of a compressive member was simulated using the Marshall model, and the nonconvergence of numerical calculation was set to be the collapse criterion. The critical wind speed, damage position, and collapse probability were obtained from a collapse analysis of the long-span transmission tower–line system under different wind attack angles. The collapse mechanism of the long-span transmission tower–line system under a wind attack angle of 45° was investigated, and an incremental dynamic analysis was performed to evaluate the collapse-resistant capacity of the transmission tower. The study reveals that the interaction between bending moment and shear deformation is critical to the collapse of transmission tower.

scholarly journals 3D FEM Soil-Structure Interaction Analysis for Kashiwazaki–Kariwa Nuclear Power Plant Considering Soil Separation and Sliding

2021 ◽  
Vol 7 ◽  
Author(s):  
Yoshitaka Ichihara ◽  
Naohiro Nakamura ◽  
Hiroshi Moritani ◽  
Byunghyun Choi ◽  
Akemi Nishida
Keyword(s):  
Seismic Data ◽  
Nuclear Power ◽  
Soil Structure ◽  
Three Dimensional ◽  
Nonlinear Behavior ◽  
Element Model ◽  
Soil Structure Interaction ◽  
Reactor Building ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

In the 2007 Niigataken Chuetsu-oki earthquake, soil settlement, considered to be a result of the relative displacement between the soil and the structure, occurred alongside buildings at Kashiwazaki–Kariwa nuclear power plant. The objective of this study is to evaluate accurately the influence of the nonlinear behavior of the soil-structure interface on the response of the reactor building using a three-dimensional finite element model. To achieve this, we modeled the separation and sliding from sidewalls during a severe earthquake using joint elements, and evaluated the effect on the horizontal response of the structure. Through the soil-structure interaction analyses based on the recorded seismic data on the foundation for unit 7 reactor building using the three-dimensional finite element model, it was confirmed that the simulated horizontal responses of the building corresponded to the recorded seismic data. In addition, the comparison of the cases with and without separation and sliding revealed that the separation and sliding of soil from sidewalls reduces the embedment effects of the structure and that the reduction causes an occurrence of the foundation uplift. Moreover, in this study, it was clarified that the increase of the foundation uplift affected both the soil pressure characteristics beneath the foundation and along the sidewalls, and the maximum acceleration response of structures. In this study, the separation and sliding of soil from sidewalls had only a limited influence on the structural responses; however, under severe seismic excitation, it is expected that the embedment effects will be significantly reduced due to the separation and sliding of soil. Therefore, a precise response evaluation of the building including the nonlinear behavior due to separation and sliding should be considered in the seismic response analyses under severe seismic excitation.

scholarly journals Inelastic dynamic analysis of steel structures

1975 ◽  
Vol 8 (4) ◽  
pp. 273-277
Author(s):  
J. Lord ◽  
J. B. Hoerner ◽  
M. Zayed
Keyword(s):  
Bending Moment ◽  
Steel Structures ◽  
Braced Frames ◽  
Moment Frames ◽  
Moment Frame ◽  
Braced Frame ◽  
Panel Zone ◽  
Aspect Ratios ◽  
Linear Behaviour ◽  
Zone Deformation

This paper updates a previously described analytical approach (1,2) using computer technology to investigate the time-dependent material non-linear behaviour of two dimensional moment-frame, truss-frame, and braced-frame steel structures during significant excursions into the post-elastic range. The approach includes considerations for energy analysis; element buckling; stable or unstable mechanism formation; yield capacity reduction resulting from interaction of axial load and bending moment; stiffness degradation; P-δ effects; viscous damping; joint panel zone deformation; and also incorporates a suitable element load-deformation relationship. The computer program NLDYN2 which incorporates this approach has been implemented successfully on many steel structures ranging from 60-story moment frames to braced frames having aspect ratios of up to 10.

scholarly journals Nonsymmetric Nonlinear Dynamics of Piezoelectrically Actuated Beams

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Mergen H. Ghayesh ◽  
Hamed Farokhi
Keyword(s):  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Nonlinear Behavior ◽  
Element Model ◽  
Piezoelectric Patch ◽  
Beam System ◽  
Piezoelectric Beam ◽  
Dimensional Finite Element ◽  
Differential Type ◽  
Three Dimensional Finite Element

The nonlinear behavior of a piezoelectrically actuated clamped–clamped beam has been examined numerically while highlighting the nonsymmetric response of the system. The nonlinearly coupled electromechanical model of the piezoelectric beam system is developed employing the Bernoulli–Euler theory along with the piezoelectric stress–voltage equations. A general nonsymmetric configuration is considered with a piezoelectric patch partially covering the beam. The geometric nonlinearities of stretching type are taken into account for both the piezoelectric patch and the beam. Through use of the generalized Hamilton's principle, the nonlinearly coupled electromechanical equations of transverse and longitudinal motions of the piezoelectrically actuated beam are derived. A high-dimensional Galerkin scheme is utilized to recast the equations of partial differential type into ordinary differential type. For comparison and benchmark purposes, a three-dimensional finite element model is developed using abaqus/cae to verify the model developed in this study. It is shown that the response of the system is strongly nonsymmetric and that it is essential to retain many degrees-of-freedom to ensure converged results.

A NEW METHODOLOGY FOR EVALUATING THE SAFE TEMPERATURE IN CONTINUOUS WELDED RAIL TRACKS

2013 ◽  
Vol 13 (02) ◽  
pp. 1350016 ◽  
Author(s):  
J. CARVALHO ◽  
J. DELGADO ◽  
R. CALÇADA ◽  
R. DELGADO
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Three Dimensional ◽  
Nonlinear Behavior ◽  
Track Structure ◽  
Compressive Stresses ◽  
Continuous Welded Rail ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Conventional Algorithm

The use of continuous welded rails (CWR) is increasingly common and is particularly important when it comes to high-speed ballasted tracks. As the longitudinal displacements are restricted in CWR tracks, a considerable rise in temperature induces compressive stresses in the rails that can lead to track buckling. Given the nonlinear behavior of the ballast, usually represented by a linear plastic model, the problem of snap-through buckling may occur, for which only a few nonlinear analysis methods can trace the full response of the track structure. However, these methods fail to yield convergent solutions for problems with thermal loads when implemented in their conventional algorithm. For this reason, a new methodology is presented allowing the calculation of the safe temperature. In addition, some analytical results are also derived for comparison with the numerical results, obtained using three-dimensional finite element beam models provided by ANSYS.

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