• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.4 s.56
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• pp.116-125
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• 2009

Recently, modular system are popular in construction fields, and they are increasing their marcket share. To compare modular units, bolting and welding are most popular methods. However, the temperature around a welded part might be over than 1,300$^{\circ}C and the composite member might be exposed tp the direct welding heat about 20,000$^{\circ}C. This high welding heat makes decrease of the concrete strength. If the concrete strength seriously decreases, it can affect the behavior and safty of a structure. On this study, To prevent of concrete strength decreases by welding heat, we suggested method of to insert between steel and concrete.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.1187-1192
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• 2005

Approximately 25% of military establishments became superannuated to unable perform their function, and it influences on the environment by construction wastes and the waste of national budget, as there is no rational and objective standard even though old facilities have been replaced through modernization project. Therefore, it has been searched to introduce industrial building system that can cope with the new building-construction and transference for the improvement of existing military establishments. However, as there is no economical estimation standard for practical use, industrial building-construction is still remaining at the initial stage, and the study is insufficient too. So. in this study, I would like to develope LCC cost model for rational LCC comparative analysis between industrial construction system (Modular) and existing reinforced concrete structure and cage, and to evaluate economical efficiency through case analysis.

• Structural Engineering and Mechanics
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• v.32 no.3
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• pp.399-406
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• 2009

A three-dimensional panel system, which was offered as a new method for construction in Jordan using relatively high strength modular panels for walls and ceilings, is investigated in this paper. The panel consists of two steel meshes on both sides of an expanded polystyrene core and connected together with a truss wire to provide a 3D system. The top face of the ceiling panel was pored with regular concrete mix, while the bottom face and both faces of the wall panels were cast by shotcreting (dry process). To investigate the structural performance of this system, an extensive experimental testing program for ceiling and wall panels subjected to static and dynamic loadings was conducted. The load-deflection curves were obtained for beam and shear wall elements and wall elements under transverse and axial loads, respectively. Static and dynamic analyses were conducted, and the performance of the proposed structural system was evaluated and compared with a typical three dimensional reinforced concrete frame system for buildings of the same floor areas and number of floors. Compressive strength capacity of a ceiling panel is determined for gravity loads, while flexural capacity is determined under the effect of wind and seismic loading. It was found that, the strength and serviceability requirements could be easily satisfied for buildings constructed using the three-dimensional panel system. The 3D panel system is superior to that of conventional frame system in its dynamic performance, due to its high stiffness to mass ratio.

• International Journal of High-Rise Buildings
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• v.3 no.1
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• pp.21-33
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• 2014

The tied braced frame (TBF) system was developed to achieve uniform seismic inelastic demand along the height of multi-storey eccentrically braced steel frames. A modular tied braced frame (M-TBF) configuration has been recently proposed to reach the same objective while reducing the large axial force demand imposed on the vertical tie members connecting the link beams together in TBFs. M-TBFs may however experience variations in storey drifts at levels where the ties have been removed to form the modules. In this paper, the possibility of reducing the discontinuity in displacement response of a 16-storey M-TBF structure by introducing energy dissipating (ED) devices between the modules is examined. Two M-TBF configurations are investigated: an M-TBF with two 8-storey modules and an M-TBF with four 4-storey modules. Three types of ED devices are studied: friction dampers (FD), buckling restrained bracing (BRB) members and self-centering energy dissipative (SCED) members. The ED devices were sized such that no additional force demand was imposed on the discontinuous tie members. Nonlinear response history analysis showed that all three ED systems can be used to reduce discontinuities in storey drifts of M-TBFs. The BRB members experienced the smallest peak deformations whereas minimum residual deformations were obtained with the SCED devices.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.5
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• pp.69-76
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• 2010

The structural material with the highest possibility of new materials that will be used in the future construction field is fiber reinforced polymer. The current studies on FRP members by using such excellent material characteristics mostly focused on stability, composite problem, and durability of FRP members. The initially constructed FRP members secure excellent stability and durability compared to reinforced concrete and steel materials, but measures for defections during the periodical inspection, methods for detecting breakages, and maintenance and reinforcement are not insufficient. Accordingly, this study proposed a measurement system using the FRP sensor to evaluate the safety of the FRP modular box member, and applied the phased array ultrasonic technique to detect the defects and damage likely to occur during the performance period.

• Steel and Composite Structures
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• v.7 no.4
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• pp.263-278
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• 2007

A finite element implementation of the modified compression field theory (MCFT) using a tangential formulation is presented in this work. Previous work reported on implementations of MCFT has concentrated mainly on secant formulations. This work describes details of the implementation of a modular algorithmic structure of a reinforced concrete constitutive model in nonlinear finite element schemes that use a Jacobian matrix in the solution of the nonlinear system of algebraic equations. The implementation was verified and validated using experimental and analytical data reported in the literature. The developed algorithm, which converges accurately and quickly, can be easily implemented in any finite element code.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.5
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• pp.333-340
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• 2019

Tests using a middle velocity propulsion impact machine (MVPIM) were performed to verify the impact resistance capability of sandwich concrete panels (SCP) in a modular liquefied natural gas (LNG) outer tank, and numerical models were constructed and analyzed. $2{\times}2m$ specimens with plain sectional characteristics and specimens including a joint section were used. A 51 kg missile was accelerated above 45 m/s and impacted to have the design code kinetic energy. Impact tests were performed twice according to the design code and once for the doubled impact speed. The numerical models for simulating impact behaviors were created by LS-DYNA. The external steel plate and filled concrete of the panel were modeled as solid elements, the studs as beam elements, and the steel plates as elasto-plastic material with fractures; the CSCM material model was used for concrete. The front plate deformations demonstrated good agreement with those of other tests. However the rear plate deformations were less. In the doubled speed test for the plain section specimen, the missile punctured both plates; however, the front plate was only fractured in the numerical analysis. The impact energy of the missile was transferred to the filled concrete in the numerical analysis.

• Nuclear Engineering and Technology
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• v.48 no.4
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• pp.893-905
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• 2016

Numerous advanced reactor concepts have been proposed to replace light water reactors ever since their establishment as the dominant technology for nuclear energy production. While most designs seek to improve cost competitiveness and safety, the implausibility of doing so with affordable materials or existing nuclear fuel infrastructure reduces the possibility of near-term deployment, especially in developing countries. The organic nuclear concept, first explored in the 1950s, offers an attractive alternative to advanced reactor designs being considered. The advent of high temperature fluids, along with advances in hydrocracking and reforming technologies driven by the oil and gas industries, make the organic concept even more viable today. We present a simple, cost-effective, and safe small modular nuclear reactor for offshore underwater deployment. The core is moderated by graphite, zirconium hydride, and organic fluid while cooled by the organic fluid. The organic coolant enables operation near atmospheric pressure and use of plain carbon steel for the reactor tank and primary coolant piping system. The core is designed to mitigate the coolant degradation seen in early organic reactors. Overall, the design provides a power density of 40 kW/L, while reducing the reactor hull size by 40% compared with a pressurized water reactor while significantly reducing capital plant costs.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.6
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• pp.26-37
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• 2008

The purpose of the study was to evaluate the effect of pervious pavements on reducing the surface runoff caused by rainfall. The surface runoff from twelve steel experimental beds with different pavement had been recorded every minute from May to September 2008, by the measuring system of tipping buckets(0.1mm/count) and data aquisition systems(National Instrument's Labview and DAQ boards & Autonics PR12-4). The dimension of the experimental bed was $1.5m(W){\times}2.0m(L){\times}0.6m(D)$ and eleven different kinds of vegetational(grass, grass+cubic stone, grass+hole brick), modular(brick, cubic stone, small cubic stone, wood block, interlocking block, clay brick, granular clay brick) and granular(naked soil, gravel) paving materials and concrete were applied for the comparison. Six rain events with depth over 30mm were selected and compared. The maximum depth of the rainfall selected was 137.5mm for 28 hours, and the minimum 30mm for 5 hours. The maximum rainfall per hour was 23mm/hr and the minimum 11.4mm/hr. The major findings were as follows; 1. All pervious pavement applied reduced over 75% of the surface runoff compared with concrete pavement. The grassy and porous pavements were relatively efficient in reducing surface runoff. 2. The grass was the more efficient as intercepting average 69.5mm of initial surface runoff, and maximum 77.8mm at the condition of 13.5mm/hr rainfall. The next was gravel intercepting maximum 65.5mm at the condition of 13.5mm/hr and the 40.9mm at 19.1mm/hr, average 55.7mm. 3. The modular pavements common in urban area were not good in intercepting the runoff except the 'clay granular brick' compared with others. The 'clay granular brick' showed relatively efficient intercepting average 14.1mm, which was the bigger amount than the 'grass+hole brick'. 4. The 'naked soil' were more effective than the 'concrete', 'brick', and 'interlocking block' in reducing the surface runoff, but less efficient than other materials. The capacity of the 'naked soil' to intercept the initial rainfall was similar to the 'brick'. As summary, the more grassy and porous pavement shows more effective in reducing surface runoffs.