• Journal of Korean Association for Spatial Structures
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• v.12 no.3
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• pp.71-78
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• 2012

The dynamic behavior of spatial structures is different depending on the aspect ration of arch structure, as the rise-span ratio or open-angle, and these spatial structures show differently the character of seismic response in accordance with stiffness and connection of the lower support structures that are directly influenced by earthquake. Therefore, in this paper, dynamic analysis is conducted for seismic response of single layer arch structures by the influence of column's stiffness and connection, to reflect the different vertical and horizontal vibration mode of single layer arch structures. The vertical response of single layer arch structures is more influence by lower columns and the influence of column's connection rotational stiffness is not large, except to the hinged connections.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.435-438
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• 2005

The use of new hybrid systems that combine the advantages of steel and reinforced concrete structures has gained popularity. One of these new mixed systems consists of steel beams and reinforced concrete shear wall, which represents a cost- and time-effective type of construction. A number of previous studies have focused on examining the seismic response of steel coupling beams in a hybrid wall system. However, the shear transfer of steel coupling beam-wall connections with panel shear failure has not been thoroughly investigated. The objective of this research was to investigate the seismic performance of steel coupling beamwall connections governed by panel shear failure. To evaluate the contribution of each mechanism, depending upon connection details, an experimental study was carried out The test variables included the reinforcement details that confer a ductile behaviour on the steel coupling beam-wall connection, i.e., the face bearing plates and the horizontal ties in the panel region of steel coupling beam-wall connections. It investigates the seismic behaviour of the steel coupling beams-wall connections in terms of the deformation characteristics. The results and discussion presented in this paper provide background for a companion paper that includes a design model for calculating panel shear strength of the steel coupling beam-wall connections.

• Steel and Composite Structures
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• v.23 no.4
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• pp.399-408
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• 2017

This paper experimentally studies the cyclic behavior of hybrid connections between steel coupling beams and concrete shear walls with embedded steel columns. Four beam-to-wall connection specimens with short and long embedded steel columns are tested under monotonic and cyclic loads, respectively. The influence of embedment length of columns on the failure mode and performance of connections is investigated. The results show that the length of embedded steel columns has significant effect on the failure mode of connections. A connection with a long embedded column has a better stiffness, load-bearing capacity and ductility than that of a short embedded column. The former fails due to the shear yielding of column web in the joint panel, while failure of the latter is initiated by the yielding of horizontal reinforcement in the wall due to the rigid rotation of the column. It is recommended that embedded steel columns should be placed along the entire height of shear walls to facilitate construction and enhance the ductility.

• Earthquakes and Structures
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• v.25 no.5
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• pp.307-323
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• 2023

This study compares two prominent design provisions, National Design Specification (NDS) and Eurocode 5, on load-carrying capacity calculations and failure analysis for mortise-tenon joints. Design procedures of double-shear connection from both provisions were used to calculate load-carrying capacity of mortise-tenon joints with eight different bolt sizes. From this calculation, the result was validated using finite element analysis and failure criteria models. Although both provisions share similar failure modes, their distinct calculation methods significantly influence the design load-carrying capacity values. Notably, Eurocode 5 predicts a 6% higher design load-carrying capacity for mortise-tenon joints with varying bolt diameters under horizontal loads and 14% higher under vertical loads compared to NDS. However, the results from failure criteria models indicate that NDS closely aligns with the actual load-carrying capacity. This indicates that Eurocode 5 presents a less conservative design and potentially requires fewer fasteners in the final timber connection design. This evaluation initiates the potential for the development of a wider range of timber connections, including mortise-tenon joints with wooden pegs.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1996.10a
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• pp.121-128
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• 1996

In this study design and construction technique for joint-less integral abutment for short to mid span bridges was developed. Expansion of superstructure due to thermal effect was absorbed in the flexible pile-type abutment in stead of expansion joint in the conventional bridges. Design method for pile subject to vertical and horizontal force was proposed. Backfill, approach slab and details of its connection joint with pavement was also proposed.

• Communications of the Korean Mathematical Society
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• v.36 no.3
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• pp.575-592
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• 2021

In this paper, we introduce the Berger type deformed Sasaki metric on the cotangent bundle T^*M over an anti-paraKähler manifold (M, 𝜑, g) as a new natural metric with respect to g non-rigid on T^*M. Firstly, we investigate the Levi-Civita connection of this metric. Secondly, we study the curvature tensor and also we characterize the scalar curvature.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.6
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• pp.18-28
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• 2015

The purpose of this study is to develop a new seismic resistant method by using precast concrete wall panels for existing low-rise, reinforced concrete beam-column buildings such as school buildings. Three quasi-static hysteresis loading tests were performed on one unreinforced beam-column specimen and two reinforced specimens with U-type precast wall panels. The results were analyzed to find that the specimen with anchored connection experienced shear failure, while the other specimen with steel plate connection principally manifested flexural failure. The ultimate strength of the specimens was determined to be the weaker of the shear strength of top connection and flexural strength at the critical section of precast panel. In this setup of U-type panel specimens, if a push loading is applied to the reinforced concrete column on one side and push the precast concrete panel, a pull loading from upper shear connection is to be applied to the other side of the top shear connection of precast panel. Since the composite flexural behavior of the two members govern the total behavior during the push loading process, the ultimate horizontal resistance of this specimen was not directly influenced by shear strength at the top connection of precast panel. However, the RC column and PC wall panel member mainly exhibited non-composite behavior during the pull loading process. The ultimate horizontal resistance was directly influenced by the shear strength of top connection because the pull loading from the beam applied directly to the upper shear connection. The analytical result for the internal shear resistance at the connection pursuant to the anchor shear design of ACI 318M-11 Appendix-D, agreed with the experimental result based on the elastic analysis of Midas-Zen by using the largest loading from experiment.

• Wind and Structures
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• v.39 no.2
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• pp.141-161
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• 2024

Engineering structures often suffer significant damage in the horizontal outflow region of downburst. The wall jet model, which simplifies the simulation device by only modeling the horizontal outflow region of downburst, has been widely employed to study downburst flow characteristics. However, research on downburst wind fields over hilly terrain using the wall jet model is limited, and the relationship between the downburst wind fields generated by wall jet and impinging jet remains unclear. This study investigates the flow characteristics of downburst-like wind over a 3D ideal hill model using wind tunnel tests with the wall jet and impinging jet models. The effects of hill height, slope, shape, and radial position on the speed-up ratio are examined using the wall jet flow. The results indicate that slope and radial position significantly affect the speed-up ratio, while hill height have a slight impact and shape have a minimal impact. Additionally, this study investigates the wind field characteristics over flat terrain using the impinging jet, and investigated the connection between the impinging jet model and the wall jet. Based on this connection, a comparison of the downburst-like flow characteristics over the same 3D ideal hill using the wall jet and impinging jet models is conducted, which further validates the reliability of the wall jet model for studying downburst flow characteristics over hilly terrain.

• Journal of the Korean Society of Safety
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• v.32 no.3
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• pp.60-65
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• 2017

This study examined the effect of rotational stiffness of joints between vertical and horizontal members in system supports. In order to prevent repeated disasters of system supports, it is important to examine the accurate behavior of system supports. Among various factors affecting the complex behavior of system supports, this study focused on the stiffness of joints between vertical and horizontal members. The considered joint was modelled by a rotational spring, but the translational displacements were fixed. The stiffness of rotational spring was calculated by utilizing the usable experimental data. In addition, the hinge connection condition, which is generally considered in design and only restrict the translational displacements, was modelled to compare the results. The case with the rotational stiffness in joints showed 3.5 times buckling loads compared to the case without the rotational stiffness. Thus, the structural behavior of the vertical member in system supports was similar to the vertical member with the fixed condition. For the combined stresses of vertical members, the combined stress ratios were reduced 5~6% by considering the rotational stiffness of connecting parts. However, for the horizontal member where showed relatively small stress range, the stresses were increased 2.3~7.6 times by considering the rotational stiffness in connecting parts.

• Journal of Korean Society of Steel Construction
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• v.17 no.3 s.76
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• pp.375-384
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• 2005

The goal of this paper is to understand the stress-transfer mechanism of concrete-filled tubular column to H-beam connections with external T-stiffener through the finite element method and to offer basic data for the design of T-stiffener. To identify the problems of previous test results, the same shapes of the full-scale test specimens were modeled for the finite element analysis. Results of the analysis were compared with the test results. Several stress and strain indices were used to understand the stress-transfer mechanism of connection with various T-stiffeners parameters. The models of analysis with different T-stiffener are grouped into TS, TSD, and TSH series. An alternative plan that decreases the stress concentration of beam flange to horizontal stiffener connection is proposed through the elasto-plastic finite element method. The basic design idea and minimum sizes of T-stiffener were proposed based on the various indices in relation to the connection details.