• Title/Summary/Keyword: similitude

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Behavior of Reinforced Earth Retaining Wall by Shaking Table Test (진동대 모형실험을 통한 보강토 옹벽의 거동 특성)

  • Yoon, Won-Sub;Yoon, Bu-Yeol
    • Journal of the Korean Society of Industry Convergence
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    • v.22 no.6
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    • pp.637-647
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    • 2019
  • In this study, we analyzed seismic behavior of reinforced earth retaining wall through the model test in order to characterize the behavior of reinforced earth retaining wall during earthquake. A scale model test was performed based on similitude ratio in accordance with law of similitude due to time and financial constraints on real scale modeling experiments. Seismic resistance characteristics of each seismic waves were analyzed by assessing the variations measured through excitation of the excited acceleration of 0.05g, 0.1g, 0.15g, and 0.2g. The results of this study, it would be important to obtain reasonable and abundant data on ground properties and seismic design in preparation for earthquakes when assessing the safety of block type reinforced earth retaining wall confined to model experiment. Acquisition of those data and systematic analytical techniques are considered likely to have a significant effect on the decrease of structure damage caused by earthquakes in Korea which has recently witnessed frequent occurrence of earthquakes.

A Study About Effects of Ice Making Processes on Variation in Physical Properties of a Model Ice Sheet (빙 생성 공정이 모형빙판의 물리적 특성 변화에 미치는 영향 연구)

  • Hoyong, Park;Jinho, Jang;Cheolhee, Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.59 no.6
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    • pp.355-361
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    • 2022
  • In order to produce model ice sheets having targeted physical properties in accordance with the law of similitude, the ice model basin of Korea Research Institute of Ships and Ocean Engineering carries out a series of processes such as cooling, seeding, freezing, and tempering. Performance in ice field of ice going ships or marine structures is evaluated from model tests in ice conditions made out of a model ice sheet such as level ice, pack ice, brash ice, and ice rubble field, etc. In this study, we investigated effects of micro-bubble layers and seeding of ice nuclei included in the process generating a model ice sheet on change in physical properties of thickness, density, and flexural strength.

Simulating large scale structural members by using Buckingham theorem: Case study

  • Muaid A. Shhatha
    • Advances in Computational Design
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    • v.8 no.2
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    • pp.133-145
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    • 2023
  • Scaling and similitude large scale structural member to small scale model is considered the most important matter for the experimental tests because of the difficulty in controlling, lack of capacities and expenses, furthermore that most of MSc and PhD students suffering from choosing the suitable specimen before starting their experimental study. The current study adopts to take large scale slab with opening as a case study of structural member where the slab is squared with central squared opening, the boundary condition is fixed from all sides, the load represents by four concentrated force in four corners of opening, as well as, the study adopts Buckingham theorem which has been used for scaling, all the parameters of the problem have been formed in dimensionless groups, the main groups have been connected by a relations, those relations are represented by force, maximum stress and maximum displacement. Finite element method by ANSYS R18.1 has been used for analyzing and forming relations for the large scale member. Prediction analysis has been computed for three small scale models by depending on the formed relations of the large scale member. It is found that Buckingham theorem is considered suitable way for creating relations among the parameters for any structural problem then making similitude and scaling the large scale members to small scale members. Finally, verification between the prediction and theoretical results has been done, it is observed that the maximum deviation between them is not more than 2.4%.

Effective Method for Analysis of Heterogeneous Porous Media (비균질 다공성 매질의 효율적 해석 방법)

  • Park, Chang-Geun
    • Journal of Korea Water Resources Association
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    • v.31 no.4
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    • pp.459-467
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    • 1998
  • The existing methods to analyze the heterogeneous porous media based on the similar media concept are the microscopic Miller similitude(MiS), the macroscopic Miller similitude(MaS) and the Warrick similitude(WS). The inter-relationship is found such that MiS ⊂ MaS ⊂ (⊂:subset). The proposed method is based ont eh assumption that the scale variables $\alpha$=w and the moisture content is dimensionless by introducing the effective degree of saturation instead of the degree of saturation into WS. The method, without the loss of generality in view of the inspectional analysis, can explain the heterogeneity of the media by using the scale variable $\alpha$ only. The media of $\alpha$=1 (average of $\alpha$) means the equivalent media corresponding to the heterogeneous media, while the standard deviation of $\alpha$ may explain the degree of the heterogeneity of the media under consideration. The hydraulic conductivity of the media with $\alpha$>1 is greater than that of the equivalent media, and the effective moisture content of the media with $\alpha$>1 is also greater. Based on these properties of the scale variable $\alpha$, the ideal vertical one-dimensional heterogeneous porous media is generated by using the technique of random number generation.

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Correlation embodiment between parts for efficient BOM use (효율적인 BOM 사용을 위한 부품간의 상관관계 구현)

  • 권영훈;김성근
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.188-192
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    • 1997
  • A study was conducted to improve validity in new BOM structure through using the similitude of existing BOM in the PDM. The system is developed in Web-Based PDM environments using servlets and database. The system provides the correlation information between parts to inflect the reusability of existing BOM. User-defined correlation is used to inform the relations between design precedence and co-relations of parameters. Realistic application in injection mold production is constructed using this structure.

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Fragility Analysis of A Scaled Model of Reinforced Concrete Column in Accordance with Similitude Law (상사법칙이 적용된 철근콘크리트 기둥 축소모형의 지진 취약도 분석)

  • Park, Dong Uk;Jeon, Bub Gyu;Kim, Nam Sik;Park, Jamin;Cho, Jae-Yeol
    • Journal of the Earthquake Engineering Society of Korea
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    • v.21 no.2
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    • pp.87-93
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    • 2017
  • Many studies are conducted in several fields for fragility analysis of structures or elements which is a probabilistic seismic safety analysis in consideration with uncertainty of seismic loading. It is hard to directly conduct fragility analysis for an infrastructure with social importance due to its size. Therefore, a fragility analysis for an infrastructure mainly conducted in element level or conducted with scaled model built in accordance with similarity law. In this article, fragility analysis for prototype and scaled model of reinforced concrete column was conducted with numerical models which had been updated by the results of shaking table test and pseudo dynamic test. As a result, response stress from the numerical analysis result of prototype model was higher than that from scaled model due to different stiffness ratios between steel and concrete. However, the probability of failure for scaled model was higher than that for prototype model because failure criteria for scaled model was down due to similarity law. Also it was evaluated that probability of failure by using log normal standard deviation of response stresses by spectrum matched accelerograms was more reliable than probability of failure by using existing coefficient of variation normally used.

Failure Mechanism of Geosynthetic Reinforced Segmental Retaining Well in Tiered Configuration Using Reduced-scale Model Tests (축소 모형 실험에 의한 계단식 보강토옹벽의 파괴 메카니즘)

  • Yoo Chung-Sik;Jung Hyuk-Sang;Jeon Sang-Soo;Lee Bong-Won;Kim Ki-Yeon;Jeon Han-Yong
    • Journal of the Korean Geotechnical Society
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    • v.21 no.3
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    • pp.65-77
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    • 2005
  • This paper investigates the failure mechanism of geosynthetic-reinforced segmental retaining walls with tiered configuration using reduced-scale model tests. The reduced scale model test set-up was established to simulate a 5 m high full-scale wall. The geometry and material properties used in the model test were determined based on the Similitude Laws. The wall failures in the model tests were successfully generated by their self weight without any surface loading and analyzed examining the digital video recordings. The failure mechanisms was examined with respect to the various offsets between the lower and upper teres and the reinforcement length. Based on the results the appropriateness of the current design guideline was discussed.

Structural behavior of arch dams considering experimentally validated prototype model using similitude and scaling laws

  • Altunisik, Ahmet Can;Kalkan, Ebru;Basaga, Hasan B.
    • Computers and Concrete
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    • v.22 no.1
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    • pp.101-116
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    • 2018
  • As one of the most important engineering structures, arch dams are huge constructions built with human hands and have strategical importance. Because of the fact that long construction duration, water supply, financial reasons, major loss of life and material since failure etc., the design of arch dams is very important problem and should be done by expert engineers to determine the structural behavior more accurately. Finite element analyses and non-destructive experimental measurements can be used to investigate the structural response, but there are some difficulties such as spending a long time while modelling, analysis and in-situ testing. Therefore, it is more useful to conduct the research on the laboratory conditions and to transform the obtained results into real constructions. Within the scope of this study, it is aimed to determine the structural behavior of arch dams considering experimentally validated prototype laboratory model using similitude and scaling laws. Type-1 arch dam, which is one of five arch dam types suggested at the "Arch Dams" Symposium in England in 1968 is selected as reference prototype model. The dam is built considering dam-reservoir-foundation interaction and ambient vibration tests are performed to validate the finite element results such as dynamic characteristics, displacements, principal stresses and strains. These results are considered as reference parameters and used to determine the real arch dam response with different scales factors such as 335, 400, 416.67 and 450. These values are selected by considering previously examined dam projects. Arch heights are calculated as 201 m, 240 m, 250 m and 270 m, respectively. The structural response is investigated between the model and prototype by using similarity requirements, field equations, scaling laws etc. To validate these results, finite element models are enlarged in the same scales and analyses are repeated to obtain the dynamic characteristics, displacements, principal stresses and strains. At the end of the study, it is seen that there is a good agreement between all results obtained by similarity requirements with scaling laws and enlarged finite element models.

Experimental Study on Nonlinear Behaviors of A 1:12 Scale 10-Story Reinforced Concrete Frame with Nonseismic Details (비내진 상세를 가진 1:12축소 10층 R.C.골조의 비선형 거동에 관한 실험 연구)

  • Lee, Han-Seon;Kang, Kyi-Yong
    • Magazine of the Korea Concrete Institute
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    • v.11 no.1
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    • pp.255-266
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    • 1999
  • The objective of this experiment is to observe the elastic and inelastic behaviors of high-rise reinforced concrete frames having non-seismic details. To do this, a building frame designed according to Korean seismic code and detailed in the Korean conventional practice was selected. A 1:12 scale plane frame model was manufactured according to similitude law. A reversed lateral load test and a monotonic pushover test were performed under the displacement control. To simulate the earthquake effects, the lateral force distribution was maintained to be an inverse triangle by using a whiffle tree. From the tests, base shears, crack pattern, local rotations in the ends of critical members and the relations between interstory drift versus story shear are obtained. Based on test results, conclusions are drawn on the implications of the elastic and inelastic behaviors of a high-rise reinforced concrete frame having non-seismic details.

Reversed Cyclic Latcral Load Test of A 2-Bay 2-Story Reinforced Concrete Frame With Seismic Detail (내진상세를 가진 2경간 2층 철근콘크리트 골조의 반복횡하중 실험)

  • Lee, Han-Seon;Woo, Sung-Woo
    • Magazine of the Korea Concrete Institute
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    • v.8 no.6
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    • pp.183-193
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    • 1996
  • The objective of this study is to investigate the characteristics of elastic and inelastic bekavior of ductile momenting-resisting reinforced concrete frame subjected to reversed lateral loading such as earthquake excitations. For this purpose, a 2-bay 2-story reinforced concrete plane frame with seismic detail was designed and one 1/2.5-scale subassemblage was manufactured according to the required similitude law. Then, the reversed load test under the displacement control was performed statically to this subassemblage. Finally, the results of this test were analysed regarding to (1) the design load vs actual strength, (2) degradation in stiffness and strength. (3) failure mode or energy dissipation. (4) local deformations.