• Journal of KSNVE
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• v.7 no.1
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• pp.153-159
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• 1997

In a stiffened plate reinforced on one of its sides by beam type stiffeners, the asymmetry about the plate mid-plane induces coupling between flexural wave and longitudinal wave. In this research interactions between flexural and longitudinal wave motion are analyzed in a stiffened plate which is reinforced only in one direction. The plate is modelled as a beam to which offset spring-mounted masses are attached at regular intervals. Propagation constants of the coupled waves and corresponding characteristic waves are derived by using periodic structure theory, and a computer code is developed. Also, sample calculations are carried out and the results are discussed.

• Special Issue of the Society of Naval Architects of Korea
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• 2009.09a
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• pp.65-70
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• 2009

In case that tug boat pushes side structures of other large vessels to maneuver, it is required that contacted side structures of the maneuvered vessels have enough structural safety against tug push loads. The objective of this study is to evaluate the structural effect of carling which is installed between side longitudinal stiffeners. A comparative study of side structures with carling and without carling is performed to evaluate the effect of carling member by both FE analysis. According to the result, it is found that the carlings play effective role in the strength of side plates and side longitudinal stiffeners against tug push loads.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.657-660
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• 2002

In this paper, a study on the residual stress of plate with longitudinal stiffeners is explained in terms of the welding sequences. In order to verify the results of numerical analysis, the hole drilling method (HDM) is performed, to measuring the residual stresses of the test plates in $CO_2$ Flux Cored Arc Welding (FCAW) under various welding conditions. The non-linear transient analysis technique for the numerical analysis in a large and complicate structure is considered. The residual stress of plate in consideration of the welding sequences and directions is evaluated by some numerical simulations and also by experiments. Comparison of numerical analysis results with experimental data shows the accuracy and validity of the proposed method.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1995.10a
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• pp.27-34
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• 1995

Elastic and in-elastic buckling stress analyses are executed by the semi-analytical finite strip method to study the effect of the longitudinal stiffener on the web of box girders. The simple analysis procedure is based on the assumption that the vertical stiffeners has the rigidity enough to force nil deflection line on the web panel so that the boundary condition may be regarded as a hinge. The provisions on the longitudinal stiffeners in plate girders of the Korean Standard Highway Bridge Specifications(1992) are investigated through comparison with the results obtained for various web stiffener size of box girders of the medium span length bridges.

• International Journal of Korean Welding Society
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• v.4 no.1
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• pp.10-14
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• 2004

In this paper, a study on the residual stress of plate with longitudinal stiffeners is explained in terms of the welding sequences. In order to verify the results of numerical analysis, the hole drilling method (HDM) is performed, to measuring the residual stresses of the test plates in $CO_2$ Flux Cored Arc Welding (FCAW) under various welding conditions. The non-linear transient analysis technique for the numerical analysis in a large and complicate structure is considered. The residual stress of plate in consideration of the welding sequences and directions is evaluated by some numerical simulations and also by experiments. Comparison of numerical analysis results with experimental data shows the accuracy and validity of the proposed method.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.6
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• pp.512-519
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• 2013

It is important to understand the vibrating behavior of plate structures for its many engineering applications. In this study, the vibration characteristics of strip plates that have finite width and infinite length are investigated theoretically and numerically. The waveguide finite element(WFE) approach, which is an effective tool for studying waveguide structures, is used in this study. The WFE method requires only a cross-sectional finite element model, and uses theoretical harmonic solutions to assess wave propagation along the longitudinal direction. First, WFE results for a simple strip plate are compared with the theoretical results(i.e., dispersion diagrams and point mobilities) to validate the numerical model. Then, in the numerical analysis, different numbers of longitudinal stiffeners are included in the plate model to investigate the effects of stiffeners in terms of the dispersion curves and mobilities. Finally, the dispersion curves of a stiffened double plate are obtained to examine the characteristics of its wave propagation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.949-954
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• 2013

Generally, structural plates under axial compression should be stiffened by longitudinal stiffeners in order to enhance the buckling strength. Though U-shaped ribs would be more efficient for the stiffened plate system, there is in the absence of a proper design guides or relevant research results. Thus this study is aimed to examine the local buckling behavior of stiffened plates with U-section ribs. 3-dimensional analysis models which include 3 types of U-shaped longitudinal stiffeners were simulated by using the finite element code ABAQUS. The bifurcation analysis were conducted and then the buckling analysis results are compared with the theoretical equation values. It is found that the rotational constraint effect provided by the U-ribs should increase the local buckling strength. Some features drawn from a series of parametric study results are summarized.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4A
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• pp.457-463
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• 2008

The longitudinal stiffener performs its role to increase the local buckling strength by making simple support upon compression flange. In the recent researches, it is investigated that compression flange with point supports on certain arrangement reveals the same strength with longitudinal stiffeners. From this results, it is predictable that shear stud could perform the role of longitudinal stiffener if shear stud embedded in concrete satisfies the requirement to point-support under yield stress of the compression flange. In this study, the researches were performed to investigate the optimally required arrangement space of longitudinal point-support for which the shear stud replacing the longitudinal stiffeners and simultaneously determine the required numbers and space of shear stud for completely composite behavior between compression bottom flange and bottom concrete on the double composite girder system.

• Structural Engineering and Mechanics
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• v.74 no.2
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• pp.255-266
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• 2020

The main requirements of modern welded metal structures are the load-carrying capacity (safety), fitness for production, and economy. The primary objective of attaching longitudinal stiffeners is to improve the buckling strength of relatively thin compression panels. This paper gives several comparisons for stiffened plates with different loadings (static, dynamic), different shape of stiffeners (flat, L-shape, trapezoidal), different steel grades, and different welding technologies (SMAW, GMAW, SAW), different costs to show the necessity of a combination of design, fabrication and economic aspects. Safety and fitness for production are guaranteed by fulfilling the design and fabrication constraints. The economy is achieved by minimizing the cost function. It is shown that the optimum sizes depend on the welding technology, the material yield stress, the profile of the stiffeners, the load cycles and the place of the production.

• Steel and Composite Structures
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• v.34 no.3
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• pp.377-391
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• 2020

A concrete filled steel tube (CFT) column with stiffeners has preferable behavior subjected to axial loading condition due to delay local buckling of the steel wall than traditional CFT columns without stiffeners. Welding lines in welded built-up steel box columns is expected to behave as longitudinal stiffeners. This study has presented a numerical investigation into the behavior of built-up concrete filled steel tube columns under axial pressure. At first stage, a finite element model (FE) has been built to simulate the behavior of built-up CFT columns. Comparing the results of FE and test has shown that numerical model passes the desired conditions and could accurately predict the axial performance of CFT column. Also, by the raise of steel tube thickness, the load bearing capacity of columns has been increased due to higher confinement effect. Also, the raise of concrete strength with greater cross section is led to a higher load bearing capacity compared to the steel tube thickness increment. In CFT columns with greater cross section, concrete strength has a higher influence on load bearing capacity which is noticeable in columns with more welding lines.