• Title/Summary/Keyword: form-finding analysis

Search Result 192, Processing Time 0.029 seconds

Seismic assessment of base-isolated nuclear power plants

  • Farmanbordar, Babak;Adnan, Azlan Bin;Tahir, Mahmood Md.;Faridmehr, Iman
    • Advances in Computational Design
    • /
    • v.2 no.3
    • /
    • pp.211-223
    • /
    • 2017
  • This research presented a numerical and experimental study on the seismic performance of first-generation base-isolated and fixed-base nuclear power plants (NPP). Three types of the base isolation system were applied to rehabilitate the first-generation nuclear power plants: frictional pendulum (FP), high-damping rubber (HDR) and lead-rubber (LR) base isolation. Also, an Excel program was proposed for the design of the abovementioned base isolators in accordance with UBC 97 and the Japan Society of Base Isolation Regulation. The seismic assessment was performed using the pushover and nonlinear time history analysis methods in accordance with the FEMA 356 regulation. To validate the adequacy of the proposed design procedure, two small-scale NPPs were constructed at Universiti Teknologi Malaysia's structural laboratory and subjected to a pushover test for two different base conditions, fixed and HDR-isolated base. The results showed that base-isolated structures achieved adequate seismic performance compared with the fixed-base one, and all three isolators led to a significant reduction in the containment's tension, overturning moment and base shear.

Effect of Bend Angle on Plastic Loads of Pipe Bends Under Internal Pressure and In-Plane Bending (내압과 굽힘하중을 받는 곡관의 소성 하중에 굽힘 각도가 미치는 영향)

  • Lee, Kuk-Hee;Oh, Chang-Sik;Yoo, Bong;Park, Chi-Yong;Kim, Yun-Jae
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.31 no.3 s.258
    • /
    • pp.322-330
    • /
    • 2007
  • This paper quantifies the effect of a bend angle of a pipe bend on plastic loads, via small strain and large strain FE limit analyses using elastic-perfectly plastic materials. To consider the effect of the attached straight pipe, two limiting cases are considered. One case corresponds to the pipe bend without the attached straight pipe, and the other to that with a sufficiently long attached straight pipe. For the former case, the FE results suggest that the limit load is not affected by the bend angle for both in-plane bending and internal pressure. For the latter case, however, the bend angle affects plastic loads. An interesting finding is that the plastic load smoothly changes from the limit load of the straight pipe when the bend angle approaches zero to the plastic load of the $90^{\circ}$ pipe bend when the bend angle approaches 90 degree. Based on such observations, closed-form plastic load solutions are proposed for the pipe bend with an arbitrary bend angle under in-plane bending and internal pressure.

A Study on the Expression by Anamorphose Phenomenon (아나모르포즈(anamorphose)지각현상에 의한 공간 표현 연구)

  • Lee, Jeong-Yoon;Kim, Kai-Chun
    • Korean Institute of Interior Design Journal
    • /
    • v.23 no.4
    • /
    • pp.63-71
    • /
    • 2014
  • Anamorphosis is highly favored in modern days as the atmosphere of pursuing unusual manners is growing while transformation and distortion of images are freely available. This research is to understand the affect of these distorted images on space designs and the close connection between anamorphosis and visual perceptions, and to identify the new perceptual phenomenon created through it, and the methods of expressing those. Four expressional methods were defined through the process of studying Anamorphosis based on its definition by Niceron, examining artworks such as paintings and photographs, and case-studying example spaces of visual perception experiments. Expressing anamorphosis through visual perceptions are broadly categorized to directional, dimensional, flatness, and optical. The analysis of 10 case projects suggests that the experimental spaces offer joys of finding and interpreting metaphorical forms and meanings caused by the four characteristic categories above. Also, they artificially show the boundaries between reality and virtual spaces in 2-dimensional or 3-dimensional spaces, and form hyper-boundaries, new experience, and an internal mechanism that is vague and chaotic. Therefore, this research concludes that anamorphosis which is a distorted perspective, is not only a simple measure to overcome perspectival errors, but is an existence suitable to the current era, that will extend its potential and value in spatial design.

Elastic Buckling Strength of Orthotropic Plate under Combined In-Plane Shear and Bending Forces (면내 전단력과 휨을 동시에 받는 직교이방성판의 탄성좌굴강도)

  • 윤순종;박봉현;정상균
    • Composites Research
    • /
    • v.12 no.2
    • /
    • pp.46-52
    • /
    • 1999
  • In this paper result of an analytical investigation pertaining to the elastic buckling behavior of orthotropic plate under combined in-plane shear and bending forces is presented. The existing analytical solution developed for the isotropic plates is extended so that the orthotropic material properties can be taken into account in the buckling analysis of web plate. For the solution of the problems Rayleigh-Ritz method is employed. Graphical form of results for finding the elastic buckling strength of orthotropic plate under combined in-plane shear and bending forces is presented. Brief discussion on the design criteria for the shear and bending interaction is also presented.

  • PDF

Simplex Analysis of the Forward Kinematics of 6-Degree-of-Freedom Parallel Manipulators Using Constraints with the Closed-loop Kinematics(Tetrahedron) (구속조건(사면체)을 사용한 6자유도 병렬 매니퓰레이터의 정기구학의 단순화 해석)

  • Song, Se-Kyong;Kwon, Dong-Soo
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.6 no.7
    • /
    • pp.559-567
    • /
    • 2000
  • This paper proposes simple and practical methods in order to overcome complex formulation and heavy computational burden of the forward kinematics of 6 앨 3-6 type parallel manipulators. Three ap-proaches for the forward kinematics are presented : one extra sensor a modified structure and novel numerical method. The proposed methods are applied to the forward kinematics of a new 6 앨 parallel manipulator with special geometry that has three internal links three external links and a moving platform of a cone shape. The proposed methods use three tetrahedrons for finding the position and orientation vector of the moving platform. The main advantages of the appraches using tetrahedrons are to abbreviate the formulation to easily find so-lutions of the forward kinematics and to be able to practically control of the manipulator in real time.

  • PDF

Calculation of Electron concentration and Electrostatic potential profile for $Al_{x}Gal{-x}As/Ga_{x}In1$_{-x}$As/GaAs HEMT device by 2-Dimensional Quantum Mechanical analysis) (2차원 양자 역학적 해석에 의한 고속 통신용 $Al_{x}Gal{-x}As/Ga_{x}In1$_{-x}$As/GaAs HEMT 소자의 전자 농도 및 전위분포 계산)

  • 송영진;황호정
    • Journal of the Korean Institute of Telematics and Electronics A
    • /
    • v.30A no.3
    • /
    • pp.76-87
    • /
    • 1993
  • We present a self-consistent, 2-dimensional solution of the Poisson and Sch rodinger equation based on the finite difference method with a nonuniform mesh size for a AlGaAs/GaInAs/GaAs HEMT devide. During the interative self-consistent calculation, however, we calculate Schrodinger equation only a some region of device, not a fully region in order to save the moemory and the speed-up of computation, and then use the approximated data for the other region using by a interpolation method with a given values. Also we adopt the proper matrix transformation method that allows preservation of the symmetric, form of the discretized Schrodinger equation, even with the use of a nonumiform mesh size, therefor, can reduce the computation time. We calculate the wavefunction, eigenstates and the electron concentration uat channel layer nder the thermal equilibrium and the biased conditions, respectively. Also,these parameters are used to solve 2-dimensional tdistribution of potential in he entire region of device. It is proved that the method is very efficient in finding eigenstages extending over relatively large spatial area without loss of accuracy. So, it can be used rather easily in any sarbitrary modulation doped utucture.

  • PDF

A Study on the 『Shanghanlunzhujie』 in the 『Uibang-yuchwi』 (『의방유취(醫方類聚)』에 수록된 『상한론주해(傷寒論注解)』에 대한 고찰)

  • Lyu, Jeong-Ah;Jang, Woo-Chang
    • The Journal of Korean Medical History
    • /
    • v.27 no.1
    • /
    • pp.1-7
    • /
    • 2014
  • Objectives : By understanding the basic information as a text about the original script, composition and characteristic of "Shanghanlunzhujie" which is included in "Uibang-yuchwi", We are evaluating value and significance of the text today. Methods : First of all, We are finding what the original script is through comparing different editions. Then by concrete analysis about texts, We are going to determine which standards affected "Shanghanlunzhujie" and "Uibang-yuchwi", and which elements included in those texts. In addition, We are figuring out what the characteristics are in the those texts roughly. Through this consideration, We could evaluate value and significance of the text. Results & Conclusions : In the course of research, We found that this publication deserves attention in the hereditary history of the "Shanghanlun" editions. First, the version of the "Shanghanlunzhujie" in the "Uibang-yuchwi" is surely the Won(元) edition. Based on recent research findings, the Won edition is the earliest version of Chengwuji's "Zhujieshanghanlun". Not only does it contain the original contents, it restored the deleted annotations of the Song edition, constituting the most accurate "Shanghanlun" edition closest to the original form of today.

Reliability studies on RC beams exposed to fire based on IS456:2000 design methods

  • Balaji, Aneesha;Aathira, M.S.;Pillai, T.M. Madhavan;Nagarajan, Praveen
    • Structural Engineering and Mechanics
    • /
    • v.59 no.5
    • /
    • pp.853-866
    • /
    • 2016
  • This paper examines a methodology for computing the probability of structural failure of reinforced concrete beams subjected to fire. The significant load variables considered are dead load, sustained live load and fire temperature. Resistance is expressed in terms of moment capacity with random variables taken as yield strength of steel, concrete class (or grade of concrete), beam width and depth. The flexural capacity is determined based on the design equations recommended in Indian standard IS456:2000. Simplified method named $500^{\circ}C$ isotherm method detailed in Eurocode 2 is incorporated for fire design. A transient thermal analysis is conducted using finite element software ANSYS$^{(R)}$ Release15. Reliability is evaluated from the initial state to 4h of fire exposure based on the first order reliability method (FORM). A procedure is coded in MATLAB for finding the reliability index. This procedure is validated with available literature. The effect of various parameters like effective cover, yield strength of steel, grade of concrete, distribution of reinforcement bars and aggregate type on reliability indices are studied. Parameters like effective cover of concrete, yield strength of steel has a significant effect on reliability of beams. Different failure modes like limit state of flexure and limit state of shear are checked.

A Study on the Modified RLS Algorithm Using Orthogonal Input Vectors (직교 입력 벡터를 이용하는 수정된 RLS 알고리즘에 관한 연구)

  • Ahn, Bong Man;Kim, Kwang Woong;Ahn, Hyun Gyu;Han, Byoung Sung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.32 no.1
    • /
    • pp.13-19
    • /
    • 2019
  • This paper proposes an easy algorithm for finding tapped-delay-line (TDL) filter coefficients in an adaptive filter algorithm using orthogonal input signals. The proposed algorithm can be used to obtain the coefficients and errors of a TDL filter without using an inverse orthogonalization process for the orthogonal input signals. The form of the proposed algorithm in this paper has the advantages of being easy to use and similar to the familiar recursive least-squares (RLS) algorithm. In order to evaluate the proposed algorithm, system identification simulation of the $11^{th}$-order finite-impulse-response (FIR) filter was performed. It is shown that the convergence characteristics of the learning curve and the tracking ability of the coefficient vectors are similar to those of the conventional RLS analysis. Also, the derived equations and computer simulation results ensure that the proposed algorithm can be used in a similar manner to the Levinson-Durbin algorithm.

The Job Seekers Model: Comparison of the General Search Model and the Unified Approach Model

  • LEE, Dong-Hae;LEE, Sang-Ki
    • The Journal of Industrial Distribution & Business
    • /
    • v.12 no.1
    • /
    • pp.7-13
    • /
    • 2021
  • Purpose: Unemployment in its general form is a result stemming from the decisions of workers to search for a new and better paying job. In this study, the view that unemployed workers were not simply desiring any job, but one that would maximize their expected future outcome, was examined. Research design, data, and methodology: In order for collection of data and analysis, the panel dates of individual applications for job openings on job search websites were utilized to examine search effort and period for individuals. Results: It was found that the number of applications sent by a job seeker declined over their period of job searching, and that job seekers over a long duration of time tend to send relatively more applications per week throughout their entire search period. The latter finding contradicts the implications of the standard labor search effort models. Conclusions: It can be observed that these job search models fail to capture several key elements in search efforts, and that the search time for an offer is not entirely predetermined by the labor market conditions and socio-economic (individual) characteristics of the searcher. It can be shortened as he or she intensifies their job search efforts.