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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Computational Structural Engineering Institute of Korea
Journal Basic Information
Journal DOI :
The Computational Structural Engineering Institute
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Volume & Issues
Volume 28, Issue 6 - Dec 2015
Volume 28, Issue 5 - Oct 2015
Volume 28, Issue 4 - Aug 2015
Volume 28, Issue 3 - Jun 2015
Volume 28, Issue 2 - Apr 2015
Volume 28, Issue 1 - Feb 2015
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Development of the Deterioration Models for the Port Structures by the Multiple Regression Analysis and Markov Chain
Cha, Kyunghwa ; Kim, Sung-Wook ; Kim, Jung Hoon ; Park, Mi-Yun ; Kong, Jung Sik ;
Journal of the Computational Structural Engineering Institute of Korea, volume 28, issue 3, 2015, Pages 229~239
DOI : 10.7734/COSEIK.2015.28.3.229
In light of the significant increase in the quantities of goods transported and the development of the shipping industry, the frequency of usage of port structures has increased; yet, the government`s budget for the shipping & port of SOC has been reduced. Port structures require systematically effective maintenance and management trends that address their growing frequency of usage. In order to construct a productive maintenance system, it is essential to develop deterioration models of port structures that consider various characteristics, such as location, type, use, constructed level, and state of maintenance. Processes for developing such deterioration models include examining factors that cause the structures to deteriorate, collecting data on deteriorating structures, and deciding methods of estimation. The techniques used for developing the deterioration models are multiple regression analysis and Markov chain theory. Multiple regression analysis can reflect changes over time and Markov chain theory can apply status changes based on a probabilistic method. Along with these processes, the deterioration models of open-type and gravity-type wharfs were suggested.
Revaluation of Inelastic Structural Response Factor for Seismic Fragility Evaluation of Equipment
Park, Junhee ; Choi, In-Kil ;
Journal of the Computational Structural Engineering Institute of Korea, volume 28, issue 3, 2015, Pages 241~248
DOI : 10.7734/COSEIK.2015.28.3.241
There are a lot of equipment related to safety and electric power production in nuclear power plants. The structure and equipment in NPPs were generally designed considering a high safety factor to remain in the elastic zone under earthquake load. However it is needed to revaluate the seismic capacity of the structure and equipment as the magnitude of earthquake was recently increased. In this study the floor response due to the nonlinear behaviors of structure was analyzed and the inelastic structural response factor was calculated by the nonlinear time history analysis. The inelastic structural response factor was calculated by the EPRI method and the nonlinear analysis method to realistically evaluate the seismic fragility for the equipment. According to the analysis result, it was represented that the inelastic structural response factor was affected by the natural frequency of equipment, the location of equipment and the dynamic property of structure.
Collapse Modes of Steel Ordinary Concentrically Braced Frames According to Unbalanced Forces
Park, Jin-Young ; Kim, Seo-Yeon ; Hong, Suk-Jae ; Kim, Hyung-Joon ;
Journal of the Computational Structural Engineering Institute of Korea, volume 28, issue 3, 2015, Pages 249~257
DOI : 10.7734/COSEIK.2015.28.3.249
The KBC2009 first introduces the requirements about vertical unbalanced forces into the design for steel ordinary concentrically braced frames(steel OCBFs), which forces them to easily meet the target seismic performance, called as the life safety performance objective under design based earthquakes(DBEs) pursuing in the KBC2009. However, there is little information on the effects of vertical unbalanced forces to the collapse prevention performance objective under maximum considered earthquakes(MCEs) which is another target seismic performance level implicitly prescribed in ASCE 7-10. It is valuable that the collapse capacities of steel OCBFs designed according to the KBC2009 are investigated. In this paper, the collapse modes of inverted V shaped steel OCBFs excited by MCEs are investigated. The prototype buildings of 5 story steel OCBFs are designed with different site conditions and three types of unbalanced forces are considered in the design stages. The prototype buildings are evaluated their seismic performances and collapse modes by nonlinear static analyses and nonlinear dynamic analyses. Analysis results show that the unbalanced forces significantly affect the seismic performance of the prototype buildings and proper considerations of unbalanced forces are required to achieve the desirable collapse mode and the collapse prevention performance objective.
Evaluation of Shear Capacity According to Transverse Spacing of Wide Beam Shear Reinforced with Steel Plate with Openings
Choi, Jin Woong ; Kim, Min Sook ; Choi, Bong-Seob ; Lee, Young Hak ; Kim, Heecheul ;
Journal of the Computational Structural Engineering Institute of Korea, volume 28, issue 3, 2015, Pages 259~266
DOI : 10.7734/COSEIK.2015.28.3.259
In this paper, transverse shear spacing and effective depth of wide beams were considered as parameters to evaluate the shear capacity of wide beam according to transverse spacing of steel plates with openings in experimental way. The eight specimens were composed of: five specimens of shear reinforced by steel plates with openings and three non-reinforced specimens. Crack, failure mode, strain and load-displacement curve of specimens were analysed. Shear contribution of shear reinforcement is evaluated and maximum transverse spacing of shear reinforcement was proposed. Shear strength of the specimen that reinforced with three stirrup legs was higher than shear strength of the specimen that reinforced with two stirrup legs. And as the effective depth increased, shear strength was increased.
Evaluation of Shear Strength for Wide Beam using GFRP Plate Shear Reinforcement
Jo, Eunsun ; Choi, Jin Woong ; Kim, Min Sook ; Kim, Heecheul ; Lee, Young Hak ;
Journal of the Computational Structural Engineering Institute of Korea, volume 28, issue 3, 2015, Pages 267~274
DOI : 10.7734/COSEIK.2015.28.3.267
In this paper, an experimental evaluation of shear strength of wide beam is presented. By the experiment in paper, shear strength depending on parameter of shear reinforcement by GFRP plate on wide beam is investigated. Specimens are 7 of reinforced by GFRP plate with openings. The shear reinforcement is manufactured into plate shape with openings to ensure perfect integration with concrete. The test was performed on 7 specimens. The parameters are including number of shear reinforcement by GFRP plates and center-to-center spacing between vertical strip. We analysed the crack, failure mode, strain, shear strength of specimens. A calculation of the shear strength of reinforced wide beam with GFRP plate based on ACI 318-11. The result of the experiment shows that the GFRP plate is works successfully as shear reinforcement in the wide beam.
Development of Variable Voltage Sensing for Identification of Dynamic Characteristics of TLCDs
Jang, Seok-Jung ; Kim, Jun-Hee ; Min, Kyung-Won ;
Journal of the Computational Structural Engineering Institute of Korea, volume 28, issue 3, 2015, Pages 275~281
DOI : 10.7734/COSEIK.2015.28.3.275
In this study, vertical motion of a Tuned Liquid Column Damper(TLCD) is measured by a variable voltage measurement system in the electric field and design parameters of the TLCD are determined. First, nonlinear damping term of the TLCD is replaced as the equivalent viscous damping term. The natural frequency and damping ratio of dynamic characteristics of the TLCD are verified. In addition, a novel liquid level measurement system is developed for measuring vertical motion of the TLCD. For the experimental achievement, experimental characterizations of natural frequency and damping ratio of the TLCD are undertaken utilizing the developed variable voltage sensing. Also, shake table testing is performed to determine the dynamic characteristics of the TLCD. As a result, the feasibility of the proposed liquid level measurement system is verified by comparison with the capacitive type wavemeter.
Two and Three-Dimensional Analysis Comparison of Nozzles due to Internal Pressure, Thermal Load and External Load
Yoon, Hyo-Sub ; Kim, Jong-Min ; Maeng, Cheol-Soo ; Kim, Hyun-Min ; Lee, Dae-Hee ;
Journal of the Computational Structural Engineering Institute of Korea, volume 28, issue 3, 2015, Pages 283~291
DOI : 10.7734/COSEIK.2015.28.3.283
In this paper, the two-dimensional(2D) and three-dimensional(3D) analyses have been performed in order to evaluate the structural integrities and compare 2D and 3D results for nozzles attached to cylindrical shells. Three nozzles, which are currently used in the nuclear power plant, are chosen to evaluate the structural integrities, and each nozzle is subjected to internal pressure, temperature variation and external loads. It is found that the 2D analysis for internal pressure should be performed with a factor of more than 1.5 or a stress concentration factor; 2D and 3D analysis results for temperature variation are almost similar to each other regardless of cladding; and the analysis results for external loads by WRC Bulletin 297 are more conservative than the 3D analysis results.
Dynamic Properties of a Lowrise Masonry-infilled RC Frame Building Before and After Seismic Retrofit
Yu, Eunjong ; Kim, Min-Jae ; Kim, Seung-Nam ; Kim, Ji-Young ; Choi, Ki-Sun ;
Journal of the Computational Structural Engineering Institute of Korea, volume 28, issue 3, 2015, Pages 293~300
DOI : 10.7734/COSEIK.2015.28.3.293
In this study, a series of forced vibration testing and ambient vibration measurement were performed at a lowrise masonry-infilled reinforced concrete frame structure before and after seismic retrofit and its dynamic properties were extracted using system identification techniques. Also, analytical models which show similar dynamic properties to the measures ones were constructed. The system identification results showed that damping ratios in x direction along which the dampers were installed has been increased. From the comparison between the analytical models, the effective stiffness of post-installed member and post-reinforced members(shear walls and damper frames) were only 50% of gross sectional stiffness of the members, which indicates that the these members were not fully integrated with the existing structure or members. In addition, support condition of post-installed footing has to be pinned in y direction to match the dynamic properties, which is seemingly caused by the change of fixity of the soil due to the installation of new footing.
State-based Peridynamic Modeling for Dynamic Fracture of Plane Stress
Ha, Youn Doh ;
Journal of the Computational Structural Engineering Institute of Korea, volume 28, issue 3, 2015, Pages 301~307
DOI : 10.7734/COSEIK.2015.28.3.301
A bond-based peridynamic model has been shown to be capable of analyzing many of dynamic brittle fracture phenomena. However, there have been issued limitations on handling constitutive models of various materials. Especially, it assumes bonds act independently of each other, so that Poisson`s ratio for 3D model is fixed as 1/4 as well as taking only account the bond stretching results in a volume change not a shear change. In this paper a state-based peridynamic model of dynamic brittle fracture is presented. The state-based peridynamic model is a generalized peridynamic model that is able to directly use a constitutive model from the standard theory. It permits the response of a material at a point to depend collectively on the deformation of all bonds connected to the point. Thus, the volume and shear changes of the material can be reproduced by the state-based peridynamic theory. For a linearly elastic solid, a plane stress model is introduced and the damage model suitable for the state-based peridynamic model is discussed. Through a convergence study under decreasing the peridynamic nonlocal region(
-convergence), the dynamic fracture model is verified. It is also shown that the state-based peridynamic model is reliable for modeling dynamic crack propagatoin.
Dynamic Fracture Analysis with State-based Peridynamic Model: Crack Patterns on Stress Waves for Plane Stress Elastic Solid
Ha, Youn Doh ;
Journal of the Computational Structural Engineering Institute of Korea, volume 28, issue 3, 2015, Pages 309~316
DOI : 10.7734/COSEIK.2015.28.3.309
A state-based peridynamic model is able to describe a general constitutive model from the standard continuum theory. The response of a material at a point is dependent on the deformation of all bonds connected to the point within the nonlocal horizon region. Therefore, the state-based peridynamic model permits both the volume and shear changes of the material which is promising to reproduce the complicated dynamic brittle fracture phenomena, such as crack branching, secondary cracks, cascade cracks, crack coalescence, etc. In this paper, the two-dimensional state-based peridynamic model for a linear elastic plane stress solid is employed. The damage model incorporates the energy release rate and the peridynamic energy potential. For brittle glass materials, the impact of the crack-parallel compressive stress waves on the crack branching pattern is investigated. The peridynamic solution for this problem captures the main features, observed experimentally, of dynamic crack propagation and branching. Cascade cracks under strong tensile loading and secondary cracks are also well reproduced with the state-based peridynamic simulations.
Ultimate Strength of Anchorage Zone according to Geometric Parameters of Post-Tensioning Anchorage using a Finite Element Method
Kwon, Yangsu ; Kim, Jin-Kook ; Kwak, Hyo-Gyoung ;
Journal of the Computational Structural Engineering Institute of Korea, volume 28, issue 3, 2015, Pages 317~324
DOI : 10.7734/COSEIK.2015.28.3.317
The design of anchorage zone in a post-tensioned member has been started from the evaluation of the ultimate resisting capacity as well as the maximum bursting stress developed, and a lot of design codes including AASHTO and PTI describe their design equations to determine the bearing strength of concrete at the anchorage zone. However, these equations usually give conservative results because their derivation is based on the simple anchorage with a wide bearing plate in the surface without any additional consideration for the load transfer mechanism through transverse ribs on the anchorage. To assess the influence of geometric parameters related to the transverse ribs on the resisting capacity of anchorage block, experiments and analysis are conducted. After verifying the validity of numerical model conducted through correlation studies between experimental and analytical results, parametric studies with changes in the transverse ribs are followed and design recommendations for the anchorage block are suggested from the numerical results obtained.
Analytical Models for the Prediction of the Flexural Behavior for Thermal Bridge Breaker Systems embedded in Reinforced Concrete Slabs
Shin, Dong-Hyeon ; Kim, Hyung-Joon ;
Journal of the Computational Structural Engineering Institute of Korea, volume 28, issue 3, 2015, Pages 325~333
DOI : 10.7734/COSEIK.2015.28.3.325
Recently, thermal bridge breaker systems(TBBSs) applicable to RC slab-wall connections have been increasingly studied and proposed. This study also aims at proposing an analytic model which is applicable to predicting the flexural behavior of TBBS embedded in slabs from the initial elastic stages, yield states to ultimate conditions. The analytic models are developed by considering strain compatibility, force equilibrium and the constitutive law obtained from material test results. To verify the accuracy of the proposed analytic model, the moment-curvature relationship and change of neutral axis according to the loading states are compared with those of experimental results. Based on the comparison, it is verified that the proposed analytic model provides well predict the flexural behavior of TBBS embedded in slabs.