• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.4
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• pp.443-451
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• 2007

The improvement of stiffness by the increase of thickness of deck plate or the reinforcement of longitudinal rib is one method among the effective methods to control fatigue damages occurring in orthotropic steel deck. It is likely that the increase of stiffness is effective to restrain local deformation caused by axial load in the steel deck. Therefore, in this study, the parameter studies for the reinforced structural details such as the bulk-head plate and vertical rib which is established to reduce the resultant stresses in the connection parts of the longitudinal rib and floor beam were performed with FE analysis. From the results, it was known that the reinforced structural detail with the bulk-head plate in the longitudinal ribs reduced overall the principal stresses at the connection parts, but the stress concentration increased in the weld toe parts which are occurring fatigue cracks. Also, it was estimated that the reinforced structural detail with the vortical rib in the longitudinal ribs because of the reduction of stress concentration in the weld toe parts is more effective details than the bulk-head plate.

• Journal of the Society of Disaster Information
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• v.12 no.4
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• pp.422-431
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• 2016

This study was evaluated in the performance of the connection according to the details of the concrete casing segment in the prestressed composite girder by fabricating and testing specimens with different segments. A total of four comparative specimens were fabricated by using the variables of general composite girders, reinforcement or non-reinforcement, and details of reinforcing bars in the segments so as to evaluate the structural behavior of steel girders. In addition, the possibility of non-cracking grade design of segmented composite girders as well as the effects of stiffness and strength according to the loop connection types after cracking were analyzed, and the appropriateness of the crack width control both the embedded steel plate and the concrete surface were evaluated.

• Computational Structural Engineering
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• v.4 no.3
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• pp.129-135
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• 1991

This paper reports the application study of the ground reinforcement under a buried pipeline subjected to differential settlement via a finite element modeling. The soil-reinforcement interaction helps to minimize the differential settlement between the adjoining pipe segments. The settlement pattern and deformation slope of a pipeline have been evaluated for a boundary condition at the joint between a rigid structure and a pipeline. The analysis results are compared for both non-reinforced and reinforced cases to numerically evaluate the stress transfer mechanism and the effectiveness of the soil reinforcement for restraining the settlement of the pipeline.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.459-467
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• 2016

Recently, new open-cut modular construction method, which is built within a 5~7m depth below the road, was proposed for the near-surface transit system to ensure the economic feasibility of underground structures. In this paper, the precast modular construction method was developed for the low-cost and rapid construction of underground structures. For the experiment on the flexural performance of the modular slab connections, a total of eleven specimens were fabricated according to the test variables; section shape, joint type, lap length, and transverse reinforcement. The test results were compared with those of the specimens without loop joints. To verify the performance of the slab connections, the 4-point loading tests of precast RC members with loop joints were conducted. As a result of the test, the flexural performance of the half-depth specimens with a 200mm lap length of loop joints were confirmed to be similar to those of the specimens without joints.

• Journal of Korean Society of Steel Construction
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• v.10 no.3 s.36
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• pp.383-391
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• 1998

Launching truss used for constructing the precast segmental concrete bridge has upper chord, lower chord and diagonal members. And the pin is used for connecting these members. From the field loading test carried out for investigating the actual behavior of launching truss, the great difference is analyzed between measured stress and calculated stress. Based on measured value, the structural analysis are carried out about assumed abnormal behavior of connection part. From the results of analysis, it is analyzed that the abnormal behavior of connection part greatly affect the structural behavior of launching truss. In addition, from the investigation of safety of launching truss, it is evaluated that the launching truss has enough safety with normal behavior of connection part.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.6
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• pp.343-349
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• 2022

This paper proposes a new topology optimization scheme to determine optimized joints for multi-component models. The joints are modeled as zero-length high-stiffness spring elements. The spring joints are considered as mesh-independent springs based on a joint-element interpolation scheme. This enables the changing of the location of the joints regardless of the connected nodes during optimization. Because the joints are movable, the locations of the optimized joints should be aggregated at several points. In this paper, the novel joint dispersal (JD) constraint to prevent joint clustering is proposed. With the joint dispersal constraint, it is possible to determine the optimized joint location as well as optimized topologies while maintaining the minimum distance between each joint. The mechanical compliance value is considered as the objective function. Several topology optimization examples are solved to demonstrate the effect of the joint dispersal constraint.

• International Journal of Highway Engineering
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• v.14 no.3
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• pp.173-182
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• 2012

Entry and exits of the rest area are sections where designed speed can be rapidly change and also a weak traffic safety section. In addition, two tasks can be performed simultaneously at entry of the rest area, particularly searching for deceleration and parking spaces/parking sides etc. Thus, design criteria is required in order to procure the stability of accessed vehicle. In case of Korea, geometric structure design criteria of entry facilities, such as toll-gate, interchange, junction etc was established. However there are no presence in a detailed standards for geometric structure of the rest area which affiliated road facilities. In this study, Derive problems in regards to the entry of geometric structure of resting areas by utilizing a sight survey and an investigation research of traffic accidents. The survey was targeting 135 general service areas. After Classifying the design section of resting areas' entry as well as derive design elements on each section, a speed measurement by targeting entry of rest areas and car behavior surveys were performed, then each element's minimum standard was derived through the analyses. According to the speeds at the starting/end point of entrance connector road, the minimum length of the entrance connector road is decided as 40m using Slowing-down length formula and based on the driving pattern, the range of the junction setting angle of the entrance connector road is defined as $12^{\circ}{\sim}17^{\circ}$. Suggest improvement plans for existing rest areas that can be applied realistically. This should be corresponded to the standards of entry and exit of developed rest areas.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.3
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• pp.429-438
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• 1994

Three-dimensional analyses of multistory structures with wings using finite element models require tedious input data preparation, longer computation time. and larger computer memory. So this study lays emphasis on the development of efficient analysis models for a three-dimensional multistory structure with wings, including in-plane deformation of floor slabs. Since a three-dimensional multistory structure with wings is regarded as a combination of wing structures and their junction in this study, the proposed analysis models are easily applicable to multistory structures with plans in the shape of letters Y, U, H, etc. Dynamic analyses results obtained using proposed models are in excellent agreement to those acquired using three-dimensional finite element models in terms of natural vibration periods, mode shapes and displacement time history.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.5
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• pp.55-62
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• 2003

Subdomain-interface variational formulation is presented to solve a class of dynamic contact problems of composite structures. The penalty method is used for imposing inequality constraints on contact surfaces and for connecting finite element subdomains that satisfy interface compatibility conditions. As a result, any complex-shaped domain can be easily divided into independently modeled subdomains without considering the conformity of meshes on interfaces. Some advantageous features of the present method are shown through a set a numerical studies with a developed computer code.

• Journal of the Korean Institute of Gas
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• v.18 no.5
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• pp.6-11
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• 2014

To optimize the design of fuel cylinder for LNG vehicles, we introduced the design parameters of the inner and the outer tank of the vessel support structure by analyzing the structural characteristics of conventional design. We selected the inner and outer diameter of the hollow support bars and a dimension of the inner structure of the vessel among the design parameters for design optimization. In this study the temperature distribution and thermal stress of the support structure were evaluated by using the utility program as MSC/MARC. The evaluation criteria are first mode natural frequency, total transferred energy through support structure and thermal stress. The developed design satisfied the design criteria and it was made of prototype. The prototype was verified through three-dimensional vibration testing and thermal performance test.