• Journal of KIBIM
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• v.4 no.1
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• pp.1-7
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• 2014

The construction method using PC(Precast Concrete) has been widely used because the method can shorten the construction period and improve construction quality. In this paper, through the analysis of present design process for PC railway platform, design parameters on the geometry and properties were extracted and 3D information models for PC railway platform were constructed by the parametric modeling technique. Furthermore, the interface module was developed to link 3D models to the structural analysis/design sheet and database program using VBA(Visual Basic Application). This information model could be used in various areas including structural analysis and design, 2D drawing, quantity estimation and 4D simulation including clash detection.

• Nuclear Engineering and Technology
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• v.55 no.4
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• pp.1365-1381
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• 2023

In this paper, a procedure for evaluating the structural integrity of the PCSG (Printed Circuit Steam Generator) unit block is presented with a simplified FE (finite element) analysis technique by applying the homogenization method. The homogenization method converts an inhomogeneous elastic body into a homogeneous elastic body with same mechanical behaviour. This method is effective when the inhomogeneous elastic body has repetitive microstructures, and thus the method was applied to the sheet assembly among the PCSG unit block components. From the method, the homogenized equivalent elastic constants of the sheet assembly were derived. The validity of the determined material properties was verified by comparing the mechanical behaviour with the reference model. Thermo-mechanical analysis was then performed to evaluate the structural integrity of the PCSG unit block, and it was found that the contact region between the steam header and the sheet assembly is a critical point where large bending stress occurs due to the temperature difference.

• Structural Engineering and Mechanics
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• v.63 no.2
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• pp.195-206
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• 2017

This paper presents the parametric numerical analysis on the ultimate bearing capacity of the purlin-sheet roofs connected by standing seam clips. The effects of several factors on failure modes and ultimate bearing capacity of the purlins are studied, including setup of anti-sag bar, purlin type, sheet thickness and connection type et al. A simplified design formula is proposed for predicting the ultimate bearing capacity of purlins. Results show that setting the anti-sag bars can improve the ultimate bearing capacity and change the failure modes of C purlins significantly. The failure modes and ultimate bearing capacity of C purlins are significantly different from those of Z purlins, in the purlin-sheet roof connected by standing seam clips. Setting the anti-sag bars near the lower flange is more favorable for increasing the ultimate bearing capacity of purlins. The ultimate bearing capacity of C purlins increases slightly with sheet thickness increasing from 0.6 mm to 0.8 mm. The ultimate bearing capacity of the purlin-sheet roofs connected by standing seam clips is always higher than those by self-drilling screws. The predictions of the proposed design formulas are relatively in good agreement with those of EN 1993-1-3: 2006, compared with GB 50018-2002.

• Geomechanics and Engineering
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• v.16 no.3
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• pp.321-329
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• 2018

Classic braced walls use struts and wales to minimize ground movements induced by deep excavation. However, the installation of struts and wales is a time-consuming process and confines the work space. To secure a work space around the retaining structure, an anchoring system works in conjunction with a braced wall. However, anchoring cannot perform well when the shear strength of soil is low. In such a case, innovative retaining systems are required in excavation. This study proposes an innovative earth-retaining wall that uses in situ soil confined in dual sheet piles as a structural component. A numerical study was conducted to evaluate the stability of the proposed structure in cohesionless dry soil and establish a design chart. The displacement and factor of safety of the structural member were monitored and evaluated. According to the results, an increase in the clearance distance increases the depth of safe excavation. For a conservative design to secure the stability of the earth-retaining structure in cohesionless dry soil, the clearance distance should exceed 2 m, and the embedded depth should exceed 40% of the wall height. The results suggest that the proposed method can be used for 14 m of excavation without any internal support structure. The design chart can be used for the preliminary design of an earth-retaining structure using in situ soil with dual steel sheet piles in cohesionless dry soil.

• Geomechanics and Engineering
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• v.11 no.2
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• pp.309-323
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• 2016

As the forefront of structural design method, capacity spectrum method can be applied conveniently, and through this method, deformation demand of structure can be considered. However, there is no research for the seismic application in the structure of sheet pile retaining wall to report. Therefore, focusing on laterally loaded stabilizing sheet pile wall, which belongs to flexible cantilever retaining structure and meets the applying requirement of capacity spectrum method from seismic design of building structure, this paper studied an approach of seismic design of sheet pile wall based on capacity spectrum method. In the procedure, the interaction between soil and structure was simplified, and through Pushover analysis, seismic fortification standard was well associated with performance of retaining structure. In addition, by comparing the result of nonlinear time history analysis, it suggests that this approach is applicable.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.5
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• pp.129-138
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• 2006

Composite deck plate using a pre-assembled re-bar truss for slab with corrugated zinc galvanized sheet iron at manufactory, is given the improvement on design, manufacture, and performance for construction work of cast-in-place reinforced concrete slab by enabling to cast concrete directly without the form work. There are two methods in analyzing composite deck : Simplified 2D analysis and 3D analysis. Although simplified 2D analysis is being used up to date, the use of 3D analysis, allowing for the vierendeel behavior of composite deck by real configuration correlating to bar reducing, is demanded. To compare the simplified 2D analysis applied to allowable stress design with 3D analysis applied to limit state design, 8 specimen are manufactured. Main variables include the depth of slab, the length of span, the diameter of bottom bar and lattice bar, and the presence of corrugated zinc galvanized sheet iron. The comparison from the experimental result and analytical result indicates that applying of simplified 2D analysis is possible for the use of D10 with bottom bar. However, it is more reasonable to apply 3D analysis which allows to indicate vierendeel behavior considered the real configuration.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.5
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• pp.151-160
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• 2022

Owing to the recent increase in the frequency of explosion accidents, blast resistive design has garnered attention to reduce the damage of important structural elements. However, domestic research on the blast resistive structures is still insufficient, and domestic design guideline against blast loads are not documented yet. In this study, a numerical study on the RC blast resistive walls, where the test variable was the presence of FRP sheet, was performed using LS-DYNA program. Based on the numerical results, displacement-time hysteretic curve, pressure-impulse diagram, and fragility curve of the test specimens were derived. It was shown that the FRP sheet strengthening method is efficient to improve the blast resistive performance of the RC wall. Also, the strengthening effect of FRP sheet on the RC wall was stronger when the magnitude of the blast load was greater.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.6
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• pp.106-112
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• 2016

In this study, circular concrete column specimens confined by carbon sheet tube with different winding angles and different number of carbon sheet plies(3T, 5T and 7T) were tested to propose design equations and a strength reduction factor. Specimens were designed by 300 mm diameter and 600 mm height with $90^{\circ}{\pm}0^{\circ}$, $90^{\circ}{\pm}30^{\circ}$, $90^{\circ}{\pm}45^{\circ}$, $90^{\circ}{\pm}60^{\circ}$, $90^{\circ}{\pm}75^{\circ}$ and $90^{\circ}{\pm}90^{\circ}$ carbon fiber angles. A 10,000 kN UTM was used for compressive strength test of specimens by displacement control method with 0.01 mm/sec velocity. Estimation equations of compressive strength and ultimate strain of circular concrete column specimens confined by carbon sheet tube using a regression analysis and a strength reduction factor to apply ultimate strength design method of concrete were proposed. The strength reduction factor(${\phi}$) of circular concrete columns confined by carbon sheet tube was estimated as 0.64 by the Monte Carlo Analysis Method. Manufacture and construction process have to be perfectly managed by construction managers because the structural capacities of carbon tubes were depends on construction abilities of manufacturing operators.

• Korean Journal of Computational Design and Engineering
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• v.5 no.2
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• pp.113-121
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• 2000

A compact pre- and post-processor that runs on PC has been developed for the purpose of remote CAE. This includes a linear-finite-element-analysis module for on-site analysis of simple and midium-sized structural problems and an interfacing module for remote analysis of more complex cases such as nonlinear and large-scale linear problems which are cpu-consuming to solve. The software was designed to provide convenient interfacing capability for the use of client-server-type analysis. In this paper, the interface module was specially designed to use ABAQUS on the supercomputer. As a benchmark for the remote CAE, a sheet-forming simulation was perfomed on a PC networked with the supercomputer.

• Transactions of Materials Processing
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• v.31 no.1
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• pp.17-22
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• 2022

Hot stamping is widely used to manufacture structural parts to satisfy requirements of eco-friendly vehicles. Recently, hot forming technology using uncoated steel sheet is being studied to reduce cost and solve patent problems. In particular, research is focused on process technology capable of suppressing the generation of an oxide layer. To evaluate the oxide layer in the hot stamping process, Gleeble testing machine can be used to evaluate the oxide layer by controlling the temperature history and the atmosphere condition. At this time, since cooling by gas injection is impossible to protect the oxide layer on the surface of a specimen, research on a method for securing a quenching speed through natural cooling is required. This paper proposes a specimen shape design method to secure a target quenching speed through natural cooling when evaluating the oxide layer of an un-coated boron steel sheet by Gleeble test. For the evaluation of the oxide layer of the un-coated steel sheet through the Gleeble test, dog-bone and rectangular type specimens were used. In consideration of the hot stamping process, the temperature control conditions for the Gleeble test were set and the quenching speed according to the specimen shape design was measured. Finally, the quenching speed sensitivity according to shape parameter was analyzed through regression analysis. A quenching speed prediction equation was then constructed according to the shape of the specimen. The constructed quenching speed prediction equation can be used as a specimen design guideline to secure a target quenching speed when evaluating the oxide layer of an un-coated boron steel sheet by the Gleeble test.