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Gilbert A. Hartley - One of the best experts on this subject based on the ideXlab platform.
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Elastic analysis of thin plates with Beam supports
Engineering Analysis With Boundary Elements, 1994Co-Authors: Caifeng Hu, Gilbert A. HartleyAbstract:Abstract The results of analysis of thin plates supported on elastic Beams are given for two types of models, namely, a ‘boundary condition’ type in which the plate and attached Edge Beam are connected continuously, and an ‘attached Beam element’ type in which the connection is not fully displacement compatible. From these analyses, the authors believe that the paper provides some general guidelines on the numerical analysis of plates with attached Beams. For example, the discontinuation of a Beam support along a plate Edge leads to a special singular condition, and the validity of a mathematical model of this will be of interest to structural designers. The numerical modelling of thin plates is based on the direct boundary element method and the procedures employed in attaching Edge Beams are described fully. Numerical results are given for square plates for comparison with established cases, however, the procedures are basically very general purpose and have been used in solving problems involving thin plates of general plan shape and transverse loading.
Takashi Hara - One of the best experts on this subject based on the ideXlab platform.
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Numerical Analysis of R/C Cylindrical Shell with Hoop Edge Beams☆
Procedia Engineering, 2017Co-Authors: Takashi HaraAbstract:Abstract In this paper, the numerical analysis of the reinforced concrete (R/C) cylindrical shell with hoop Edge Beams was performed by using the nonlinear finite element method. R/C shell with free Edges must be stiffened by the Edge Beam. From the numerical results of the previous papers, the minimum size of the Edge Beam was placed on both hoop Edges as the Beam having the maximum ratio of the strength to the weight. There were several connecting method between R/C cylindrical panel and the hoop Edge Beam. Three kinds of connecting position between R/C shell and the Edge Beam were considered. One was the concentric connection of R/C shell and the Beam (Type C). The second one was the shell connected at the top of the Beam (Type L). The third one was the shell connected with the bottom of the Beam (Type U). R/C shell was pin supported on the meridian and free on the hoops. Quasi uniformly distributed load was applied to the model. In numerical analysis, both shells and Beams were modeled by solid elements. The reinforcements were represented by the steel sheets. To represents the nonlinear behavior of R/C shell elements, combined material and geometric nonlinearities were taken into account. The relation between an applied load and deflections as well as crack propagations was investigated. The ultimate strength of the structure was also obtained. From the numerical analyses, concentric connection of R/C shell and the Beam (Type C) was efficient. However, R/C shell connecting with the top of the Beam (Type L) showed better performance and was better connection method considering the finishing of the structure and the design demand.
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STRUCTURAL BEHAVIOR OF R/C SHELL CONSIDERING THE POSITION OF Edge Beam
Proceedings of International Structural Engineering and Construction, 2015Co-Authors: Takashi HaraAbstract:Reinforced Concrete (R/C) shell has been constructed to cover large public spaces and large industrial buildings. RC shell is originally a continuous structure and shows the large load bearing capacity. To apply these structures to such purpose, the structure is cut at any particular portion and loses their continuum properties. Therefore, Edge Beams must be placed to avoid the stress concentration and a local failure. In this paper, R/C cylindrical shell with Edge Beam on meridional free Edges was analyzed by use of FEM. RC shell had 960 x 960 mm plan and the thickness was 10 mm. The radius and the depth of the shell were 688 mm and 190 mm, respectively. As the Edge Beam, three kinds of rectangular Beams, which had 2 cm width and 4 cm depth, were arranged. One was connected to the shell at the gravity center of the Beam and the others were connected at the bottom or the top of the Beam. From the numerical analyses, the deformation and the stress distribution of the shell mentioned above were analyzed precisely. The shell connected with the gravity center of the Beam showed the smooth deformation and the stress distributions.
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Numerical Evaluation of the Effects of Edge Beams Attached to the Cylindrical R/C Shell Structures
Procedia Engineering, 2011Co-Authors: Takashi HaraAbstract:Abstract In Reinforced concrete (R/C) shell structures, the free Edges of them are not usually continuous depending on the design and the supporting purposes. To strengthen these Edges, Edge Beams are placed on such cutting Edges. To obtain the sufficient strength of such shell structures, an appropriate size of Edge Beams must be applieed. In this paper, the numerical analysis of the R/C cylindrical shell with Edge Beams by using the nonlinear finite element method. In numerical analysis, the degenerate shell elements with layered approach are adopted. Both shells and Beams are modeled by these elements. To represents the nonlinear behavior of R/C shell elements, combineed material and geometric nonlinearities are taken into account. From the numerical analyses, the stiffness of the Edge Beams plays an important role to show the deformation characteristics annd the ultimate strength of R/C shell structures. Considering the effects of Edge Beams on these phenomena, the minimum size of the Edge Beam to represent the maximum ultimate strength of cylindrical R/C shell is represented under several conditions.
Kiyotoshi Hiratsuka - One of the best experts on this subject based on the ideXlab platform.
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Dynamic Response of Base Isolated Rotational Shell with Edge Beam and Fuzzy Vibration Control of the Shell
International Journal of Space Structures, 1997Co-Authors: Kiyoshi Shingu, Kiyotoshi HiratsukaAbstract:Seismic isolation and fuzzy vibration control systems, which consist of a shell with an Edge Beam which has springs and variable dampers between the Edge Beam and the ground, are suggested by one of the authors.In this paper, natural vibration modes and natural frequencies of base isolated rotational shells with Edge Beams are shown. When the shell shakes due to vertical seismic forces, the seismic isolated system is implemented. As a result, stresses in the shell are significantly reduced.Furthermore, vibration control of the shell is carried out. Then the damping ratios are adjusted by the fuzzy theory, and stresses in the shell are further reduced.
James Michael Lafave - One of the best experts on this subject based on the ideXlab platform.
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modeling of cyclic joint shear deformation contributions in rc Beam column connections to overall frame behavior
Structural Engineering and Mechanics, 2004Co-Authors: Myoungsu Shin, James Michael LafaveAbstract:In seismic analysis of moment-resisting frames, Beam-column connections are often modeled with rigid joint zones. However, it has been demonstrated that, in ductile reinforced concrete (RC) moment- resisting frames designed based on current codes (to say nothing of older non-ductile frames), the joint zones are in fact not rigid, but rather undergo significant shear deformations that contribute greatly to global drift. Therefore, the "rigid joint" assumption may result in misinterpretation of the global performance characteristics of frames and could consequently lead to miscalculation of strength and ductility demands on constituent frame members. The primary objective of this paper is to propose a rational method for estimating the hysteretic joint shear behavior of RC connections and for incorporating this behavior into frame analysis. The authors tested four RC Edge Beam-column-slab connection subassemblies subjected to earthquake-type lateral loading; hysteretic joint shear behavior is investigated based on these tests and other laboratory tests reported in the literature. An analytical scheme employing the modified compression field theory (MCFT) is developed to approximate joint shear stress vs. joint shear strain response. A connection model capable of explicitly considering hysteretic joint shear behavior is then formulated for nonlinear structural analysis. In the model, a joint is represented by rigid elements located along the joint Edges and nonlinear rotational springs embedded in one of the four hinges linking adjacent rigid elements. The connection model is able to well represent the experimental hysteretic joint shear behavior and overall load- displacement response of connection subassemblies.
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reinforced concrete Edge Beam column slab connections subjected to earthquake loading
Magazine of Concrete Research, 2004Co-Authors: Myoungsu Shin, James Michael LafaveAbstract:Four two-thirds-scale reinforced concrete Edge Beam–column–slab subassemblies (two concentric and two eccentric connections) were tested under quasi-static cyclic lateral loading. Each subassembly represented a cruciform connection in an exterior moment-resisting frame with a monolithic floor slab on one side only, loaded in the longitudinal direction of the Edge-Beams. The tests explored the effect of eccentricity between Beam and column centrelines, and the effect of floor slabs, on the structural performance of Edge Beam–column–slab connections subjected to earthquake loading. Performance of the specimens was evaluated in terms of overall strength and stiffness, energy dissipation, Beam plastic hinge development, joint shear deformation, and joint shear strength. All specimens underwent some Beam hinging at the Beam/column interfaces. However, both eccentric specimens, and one concentric specimen with a heavily reinforced floor slab, eventually failed as a result of joint shear, whereas the other conce...
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Reinforced concrete Edge Beam?column?slab connections subjected to earthquake loading
Magazine of Concrete Research, 2004Co-Authors: Myoungsu Shin, James Michael LafaveAbstract:Four two-thirds-scale reinforced concrete Edge Beam-column-slab subassemblies (two concentric and two eccentric connections) were tested under quasi-static cyclic lateral loading. Each subassembly represented a cruciform connection in an exterior moment-resisting frame with a monolithic floor slab on one side only, loaded in the longitudinal direction of the Edge-Beams. The tests explored the effect of eccentricity between Beam and column centrelines, and the effect of floor slabs, on the structural performance of Edge Beam-column-slab connections subjected to earthquake loading. Performance of the specimens was evaluated in terms of overall strength and stiffness, energy dissipation, Beam plastic hinge development, joint shear deformation, and joint shear strength. All specimens underwent some Beam hinging at the Beam/column interfaces. However, both eccentric specimens, and one concentric specimen with a heavily reinforced floor slab, eventually failed as a result of joint shear, whereas the other concentric specimen exhibited more ductile load-displacement response. The eccentric specimens (with different eccentricities and Edge-Beam widths) underwent similar behaviour before they started to break dawn, and they also reached similar joint shear strengths. Slab participation was evaluated using slab bar strain gauge data with respect to storey drift. Actual effective slab widths were much larger than the ones typically used in design, especially for the specimens with a column wider than the Edge-Beams. Finally, floor slabs imposed significant joint shear demand, but they also increased joint shear capacity by expanding effective joint width.open111
Caifeng Hu - One of the best experts on this subject based on the ideXlab platform.
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Elastic analysis of thin plates with Beam supports
Engineering Analysis With Boundary Elements, 1994Co-Authors: Caifeng Hu, Gilbert A. HartleyAbstract:Abstract The results of analysis of thin plates supported on elastic Beams are given for two types of models, namely, a ‘boundary condition’ type in which the plate and attached Edge Beam are connected continuously, and an ‘attached Beam element’ type in which the connection is not fully displacement compatible. From these analyses, the authors believe that the paper provides some general guidelines on the numerical analysis of plates with attached Beams. For example, the discontinuation of a Beam support along a plate Edge leads to a special singular condition, and the validity of a mathematical model of this will be of interest to structural designers. The numerical modelling of thin plates is based on the direct boundary element method and the procedures employed in attaching Edge Beams are described fully. Numerical results are given for square plates for comparison with established cases, however, the procedures are basically very general purpose and have been used in solving problems involving thin plates of general plan shape and transverse loading.
