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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%.

Analytical Study on the Size Effect Influencing Inelastic Behavior of ]Reinforced Concrete Bridge Piers Subjected to Cyclic Lead (반복하중을 받는 철근콘크리트 교각의 비탄성 거동에 미치는 크기효과에 관한 해석적 연구)

  • 김태훈;신현목
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2001.09a
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    • pp.131-138
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    • 2001
  • The purpose of this study is to investigate size effect on inelastic behavior of reinf bridge piers subjected to cyclic load. A computer program, named RCAHEST(Reinforced Co Analysis in Higher Evaluation System Technologr), for the analysis of reinforced concret was used. Material nonlinearity is taken into account by comprising tensile, compressiv models of cracked concrete and a model of reinforcing steel The smeared crack app incorporated. In boundary plane at which each member with different thickness is conne discontinuous deformation due to the abrupt change in their stiffness can be taken into introducing interface element. The effect of number of load reversals with the same d amplitude has been also taken into account to model the reinforcing steel. To determine th on bridge pier inelastic behavior, a 1/4-scale replicate model was also loaded for compar full-scale bridge pier behavior.

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River Pollution Control Using Hierarchical Optimization Technique (계층적 최적화 기법을 이용한 강의 수질오염 제어)

  • 김경연;감상규
    • Journal of Environmental Science International
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    • v.4 no.1
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    • pp.71-80
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    • 1995
  • A discrete state space model for a multiple-reach river system is formulated using the dynamics of biochemical oxygen demand(BOD) and dissolved oxygen(DO). A hierarchical optimization technique, which is applicable to large-scale systems with time-delays in states, is also described to control stream quality in a river as an optimal manner based on the interaction prediction method. The steady state tracking error of the proposed method is determined analytically and a necessary and sufficient condition on which a constant target tracking problem has zero steady-state error is derived. Computer simulations for the river pollution model illustrate the algorithm.

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Scale Development for Youth Obesity Prevention and Unified Validity Test through the Health Belief Model-I (건강신념모형을 적용한 청소년 비만예방척도개발과 통합적 타당도검증-I)

  • Kim, Eung-Joon;Ko, Byoung-Goo;Cho, Eun-Hyung
    • 한국체육학회지인문사회과학편
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    • v.58 no.1
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    • pp.295-308
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    • 2019
  • The purpose of the present study is to apply a health belief model to the serious perception of an increase in youth obesity, and to develop and validate a measurement tool for youth obesity prevention among this group who are experiencing increasing rates of obesity. The specific goals of this study are to 1) apply a health belief model to develop a measurement tool for obesity prevention among youth who are seeing rising rates of obesity, and 2) provide an integrated validation procedure and foundation for developing this measurement tool. A total of 1801 high school students[sample1: 902(male:464,female:438); sample2: 899(male:464,female:438)] were recruited and collected data from 12 high school in Seoul and Kyonggi area. For this study the analytic framework of unified validity was developed which can comprehensively reflect unified validity be Messick(1995), framework for conducting a strong program of construct validation by Benson(1998), the unified validity implementation method of Rasch model suggested by Wolfe and Smith(2007a, 2007b). Furthermore, after dividing the developed analytic framework into each stage(the substantive domain), the evidence of validity of Youth Obesity Prevention Scale(YOPS) applying Health Belief Model was systematically suggested. The YOPS suggested the evidence about the substantive domain of unified validity. The developed YOPS was consist of Susceptibility, Severity, Benefits, Barriers and Cues to Action. After 3 stage in substantive domain, the components of YOPS(5factors and 28items) satisfied the unidimensionality, and the 5 point Likert scale had the significant discrimination of the respondents' response.

Estimation of Conductivity Tensor of Fractured Rocks from Single-hole Packer test (단정 주입시험 결과를 이용한 단열암반의 수리전도도 분석)

  • 장근무;이은용;김창락;이찬구;김현주
    • The Journal of Engineering Geology
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    • v.10 no.1
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    • pp.13-25
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    • 2000
  • A three-dimensional discrete fracture network model based on probabilistic characteristics of fracture geometry and transmissivity was designed to calculate the conductivity tensor and to estimate theanisotropy of conductivity. The conductivities, $K_p$, obtained from the numerical simulation of single-holepacker test corresponded well to those from the field tests. From this, it can be concluded that thefracture network model designed in this study can represent hydraulic characteristics of in-situ fractured rock mass. Block-scale conductivities, $K_b$, estimated from the modelling of steady-state flow through the REV-scale block were ranged between the arithmetic mean and harmonic mean of theconductivity estimates from packer tests. The conductivity along north-south direction was 1.4 timesgreater than that along the east-west direction. It was concluded that the anisotropy of conductivitywas insignificant. It was also found that there was a little correlation between $K_b$ and $K_p$. This would be to that the conductivities from the packer test simulation was strongly dependent on thetransmissivity and the number of fractures within the packer test intervals.

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Resisting Behavior of Fully-Grouted Rock Bolts with Compressible Spacers (압축성 간격재를 설치한 전면접착식 볼트의 인발저항 거동)

  • Hwang, Yong-Sub;Lee, Sang-Duk
    • Tunnel and Underground Space
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    • v.21 no.5
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    • pp.377-385
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    • 2011
  • In order to prove the applicability of rock bolts with compressible spacers, laboratory model tests and large scale model tests were conducted. Laboratory model tests were performed in various distance of compressible spacers to determine the optimal distance of compressible spacers. The optimal distance of compressible spacers was found that is 1/4 of rock bolts unit length. Large scale model tests that the size was 0.6 m (diameter) ${\times}$ 4.45 m (length) were conducted. Test results showed that pull out resistance could be increased up to 15% larger than that of unused case by using compressible spacers.

A Study on the Method of Extracting Ridge Shadows in Images by Using a Deformable Model (Deformable Model을 이용한 원형자동추출방법에 관한 연구)

  • 송재욱
    • Journal of the Korean Institute of Navigation
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    • v.22 no.4
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    • pp.37-44
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    • 1998
  • This paper presents a procedure for automated extraction of ridge shadows in noisy gray images. This procedure mainly consists of 1) a deformable model which is designed basing upon the knowledge about the shape of shadows and is expected to be useful in extracting ridge shadows especially located in low signal to noise ratio background, and 2) the scale space scheme which is also useful even if there is less information about the size and the positions of ridge shadows in advance. This procedure is applied to artificial images and its performance is evaluated experimentally.

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On the Study of Rationalization of Plant Layout - Orient ed Non-massing Jobbing Production Shop - (설비배치합리화에 관한 연구 - 다품종소량생산형태를 중심으로 -)

  • 조남호;이근희
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.7 no.10
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    • pp.1-16
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    • 1984
  • The purpose of this paper is to develop rational layout model for small and medium scale industry in Korea. The methodology of this paper is to light the importance of small and medium scale company. Moreover, to overcome the problem of layout in non-massing jobbing production shop this paper is proposed four techniques. So proposed layout model is obtained analytically in single, multiple facility location problem The result of this paper is as follows : First, alternatives to overcome abnormal layout in small and medium company are 1) GT (Group Technology) 2) SLP (Systematic Layout Planning) 3) OR (Operations Research) 4) Computer Second, in single facility location problem, Gradient method and square weighted average method are studied. Lastly in multiple facility location problem, heuristic method is obtained.

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A Study on the Performance Assessment of PHWR Containment Building (가압중수형 원전 격납건물의 성능평가에 관한 연구)

  • Lee, Hong-Pyo;Jang, Jung-Bum
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.4
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    • pp.449-455
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    • 2011
  • Recently, international collaborative research which was organized at Bhabha Atomic Research Centre in India, was conducted to develop for pressure capacity and nonlinear behavior of PHWR 1/4 scale nuclear containment building between experimental test and numerical code. In this paper, a nonlinear finite element analysis was carried out in order to predict ultimate pressure capacity and nonlinear behavior of the 1/4 scale containment building. The 1/4 scale containment building is consisted of basemat, cylinder wall, dome and 4-buttress. For the finite element analysis, commercial program ABAQUS was used. Finite element models including concrete, rebar and tendon have been developed for assessment of ultimate pressure capacity and failure mode for nuclear containment building. From the analysis results, first crack of the concrete, the yielding of the rebar and ultimate capacity pressure occurred at $1.6P_d$(design pressure), $3.36P_d$ and $4.0P_d$, respectively.

Convergence Study of Reliability and Validity testing for Professional Moral Courage Scale Translated in Korean (Professional Moral Courage Scale(PMCS)의 한국어 번역의 신뢰도와 타당도에 관한 융합연구)

  • Moon, Suk Ja;Kim, Dal Sook
    • Journal of the Korea Convergence Society
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    • v.8 no.3
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    • pp.151-161
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    • 2017
  • This methodological study was conducted to test a Professional Moral Courage Scale(PMCS) translated in Korean for 196 nursing students in Changwon, Korea. Data were collected from January 13 to February 20, 2017. An internal consistency reliability and construct validity using exploratory and confirmatory factor analysis were conducted. These items were categorized into 4 factors explained 62.20% of the total variance. 4 factor model was validated by CFA(${\chi}2/df=1.89$, p<.001, RMR=.055, GFI=.93, AGFI=.89, CFI=.92, RMSEA=.067). The Cronbach's ${\alpha}$ was .79 and the reliability of subscales ranged from .44 to .80. The results show that this scale can provide scientific and empirical data when evaluating the PMCS of further clinical nurses, it is meaningful in the sense that it is the first attempt to measure the moral courage needed to provide a good nursing.