• International Journal of Naval Architecture and Ocean Engineering
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• v.4 no.4
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• pp.423-436
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• 2012

Unstiffened plates are integral part of all kinds of structures such as ship and offshore oil platforms. Openings are unavoidable and absolutely reduce the ultimate strength of structures. In this study, the finite element analysis package, ABAQUS, is used to analyze the behavior of unstiffened plate with rectangular opening. The rectangular opening form is divided into two cases. In case1, opening depth is constant, but opening width is varied. Meanwhile, in case2 opening width is fixed and opening depth is varied. Besides, for the two different form opening, the effect of plate slenderness parameter (${\beta}$), opening area ratio (AR) and opening position ratio (PR) on the ultimate strength of plate with opening under axial compression are presented. It has been found that the ultimate strength of plate ofcase1is much more sensitive to the plate slenderness parameter (${\beta}$) and opening area ratio (AR) than that of case2. However, for case1, opening position (PR) almost has no effect on the ultimate strength, whereas, regardingcase2, the influence of opening position (PR) depends on the plate slenderness parameter (${\beta}$). Based on nonlinear regression analysis, three design formulae are not only developed but also approved reasonably for the practical engineering design.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.10a
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• pp.162-169
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• 1999

Intentionally weakened girders near the beam-to-colum connection lead ductile failures at the weakened points prior to potential brittle failure at the connection points subjected to strong earthquake. Recent research investigated cyclic behavior of composite beams with a rectangular web opening and find out ductile failure of such beams due to plastic hinge formation of T-section at the four corners of the rectangular opening. But eventual failures of T-sections are resulted from local buckling of T-section having a narrow stem and a narrow bound of plastic hinge formation. This continuing research proposes double-circular opening instead of rectangular one in ofter to improve energy dissipation capacity as well as composite beam strength, Experimental test of two specimens was carried out and its results are compared with those of nonlinear finite element analyses

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.1
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• pp.171-178
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• 1999

Despite of decrease in shear and moment strengths, most steel structural designers use web openings in beams because of economical benefit and requirement. The purpose of this study is to suggest the method of reinforcement of H-shape steel beams with a rectangular web opening. If shear predominates over bending, it is necessary to consider all possible combinations of shear force and bending moment acting at the opening. In this paper, the ultimate strength and behavior of perforated beams have been investigated according to parameters (ratio of M/V, opening width within opening height ratio D/h, various reinforcing types A/B/C/D/M/N/W). The results of this study are as follows ; 1. Deformation of H-shape steel beams with a rectangular web opening was greatly affected by not only bending but also shear. 2. SB1-2/3 series have little difference in the reinforced efficiency, but SB1-2E/3E series have difference in the reinforced efficiency according to the reinforcement type. 3. Efficiency of SB1-2E/3E series is determined by reinforcing types, which RB1-2E-B/M/C and RB1-3E-M/D/C specimens have good efficient. Reinforcing type of perforated beams chooses efficient method according to ratio of M/V and D/h.

• Structural Engineering and Mechanics
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• v.7 no.3
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• pp.289-302
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• 1999

An approximate method for analyzing the bending problems of irregular-shaped plates is proposed. In this paper irregular-shaped plates are such plates as plate with opening, circular plate, semi-circular plate, elliptic plate, triangular plate, skew plate, rhombic plate, trapezoidal plate or the other polygonal plates which are not uniform rectangular plates. It is shown that these irregular-shaped plates can be considered finally as a kind of rectangular plates with non-uniform thickness. An opening in a plate can be considered as an extremely thin part of the plate, and a non-rectangular plate can be translated into a circumscribed rectangular plate whose additional parts are extremely thin or thick according to the boundary conditions of the original plate. Therefore any irregular-shaped plate can be replaced by the equivalent rectangular plate with non-uniform thickness. For various types of irregular-shaped plates the convergency and accuracy of numerical solution by proposed method are investigated.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.797-801
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• 2003

This paper has the object of investigating natural frequencies of opening thick plates on Pasternak foundation by means of finite element method and providing Kinematic design data for mat of building structures. Vibration analysis that opening plate subjected to In-plane stress is presented in this paper. Finite element analysis of rectangular opening plate is done by use of rectangular finite element with 8-nodes. In order to analysis plate which is supported on Pasternak foundation, the Winkler foundation parameter is varied with 0, 10, 102, 103 and the shear foundation parameter is 0, 5, 10, 15. The ratio of In-plane force to critical load is applied as 0.2, 0.8, respectively. This paper analyzed varying opening Position and opening size.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.2
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• pp.399-408
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• 2015

This paper concentrated on the ultimate uniaxial compressive strength of stiffened panel with opening under lateral load and also studied the design-oriented formulae. For this purpose, three series of well executed experiments on longitudinal stiffened panel with rectangular opening subjected to the combined load have been selected as test models. The finite element analysis package, ABAQUS, is used for simulation with considering the large elasticplastic deflection behavior of stiffened panels. The feasibility of the numerical procedure is verified by a good agreement of experimental results and numerical results. More cases studies are executed employing nonlinear finite element method to analyze the influence of design variables on the ultimate strength of stiffened panel with opening under combined pressure. Based on data, two design formulae corresponding to different opening types are fitted, and accuracy of them is illustrated to demonstrate that they could be applied to basic design of practical engineering structure.

• International Journal of Naval Architecture and Ocean Engineering
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• v.5 no.3
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• pp.478-491
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• 2013

Natural vibration analysis of plates with openings of different shape represents an important issue in naval architecture and ocean engineering applications. In this paper, a procedure for vibration analysis of plates with openings and arbitrary edge constraints is presented. It is based on the assumed mode method, where natural frequencies and modes are determined by solving an eigenvalue problem of a multi-degree-of-freedom system matrix equation derived by using Lagrange's equations of motion. The presented solution represents an extension of a procedure for natural vibration analysis of rectangular plates without openings, which has been recently presented in the literature. The effect of an opening is taken into account in an intuitive way, i.e. by subtracting its energy from the total plate energy without opening. Illustrative numerical examples include dynamic analysis of rectangular plates with rectangular, elliptic, circular as well as oval openings with various plate thicknesses and different combinations of boundary conditions. The results are compared with those obtained by the finite element method (FEM) as well as those available in the relevant literature, and very good agreement is achieved.

• Advances in concrete construction
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• v.2 no.4
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• pp.281-300
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• 2014

This study presents the experimental results of twenty three reinforced concrete beams with rectangular web openings externally strengthened with Fiber Reinforced Polymers (FRP) composites bonded around openings. All tested beams had the same geometry and reinforcement details. At openings locations, the stirrups intercepted the openings were cut during fabrication of reinforcement cage to simulate the condition of inclusion of an opening in an existing beam. Several design parameters are considered including the opening dimensions and location in the shear zone, the wrapping configurations, and the amount and the type of the FRP composites in the vicinity of the openings. The wrapping configurations of FRP included: sheets, strips, U-shape strips, and U-shape strips with bundles of FRP strands placed at the top and sides of the beam forming a fan under the strips to achieve closed wrapping. The effect of these parameters on the failure modes, the ultimate load, and the beam stiffness were investigated. The shear contribution of FRP on the shear capacity of tested beams with web openings was estimated according to ACI Committee 440-08, Canadian Standards S6-06, and Khalifa et al. model and examined against the test results. A modification factor to account for the dimensions of opening chords was applied to the predicted gain in the shear capacity according to ACI 440-08 and CSA S6-06 for bonded Glass Fiber Reinforced Polymers (GFRP) around openings. The analytical results after incorporating the modification factor into the codes guidelines showed good agreement with the test results.

• Journal of the Korean Society of Safety
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• v.7 no.2
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• pp.30-41
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• 1992

Analysis of Dynamic Characterisocs of Rectangular Plate by Finite Element Method. Dynamic characteristics of a rectangular plate with opening in it is studied by finite element method. To investigate these characteristics 12 degrees of freedom membrane finite element in used. The rectangular membrane finite elements are defined by specifying geometry, internal displacement functions and strain-displacement relations. Then, the governing equation for the finite element is derived by energy method. To derive the mass matrix and stiffness matrix of the element, expressions for strain and kineic energy in terms of the node displacement are generated. In constructing the overall structure matrix, the matrix of each elements are superposed and partitioned by applying the given boundary condition to obtain a nonslngular matrix. To find the natural freguencies and viration modes, the eigen values and the corresponding eigen vectors are computed by the computer using well known Jacobi power method. In order to verify the capability of the membrane finite element, a flat rectangular plate is analyzed first, and the result is compared with well known analytical results to show the good agreement. A rectangular plate with opening in It is analyzed with the same finite element. The results are presented in this paper. Unfortunately, the literature study could not provide with some results to compare, but the results reveal that the output of this research is phlslcally reasonable. And the results of this research are useful not only in practice but also for the future experimental research in comparison purpose.

• Journal of Korean Society of Steel Construction
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• v.27 no.3
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• pp.289-298
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• 2015

The steel tube of Concrete-Filled Tube(CFT) confines the concrete and the concrete restrains the buckling of the tube, The objective of this study is to investigate the influences of the opening shape of the through diaphragm in case of the rectangular CFT column-to-beam connection through the structural experiment. The experiment results are compared with analysis results obtained by using the FEM program. These results are shown that strength of the rectangular CFT column-to-beam connection have similar structural performance regardless of the opening shape if opening areas of the through diaphragm are same. Also in case the connection area/shape of the through diaphragm and the flange of H-beam are similar, it was ascertained that the bending stress occurred at the beam can be transferred to the column through the diaphragm.