• Title/Summary/Keyword: Engineering procedure

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Member Selection Procedure in the Steel Structural Design (강구조물설계에서 부재선정의 시스템화 방법론)

  • 이영호;김상철;김흥국;이병해
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1995.10a
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    • pp.197-206
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    • 1995
  • In structural design procedure, The procedure of member selection manages complex data relationship and reflects structural expert's knowledge. It is a difficult problem to construct an effective system with the conventional l programming technique. Knowledge_based s!'stem is a software system capable of supporting the explicit representation of expert's knowledge in member selection process through member data and reasoning mechanisms. This study describes useful methodology for structuring knowledge and representing relation between member data and knowledge. And this study shows the application of this member for member selection in the steel structural design.

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An efficient three-dimensional fluid hyper-element for dynamic analysis of concrete arch dams

  • Lotfi, Vahid
    • Structural Engineering and Mechanics
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    • v.24 no.6
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    • pp.683-698
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    • 2006
  • The accurate dynamic analysis of concrete arch dams relies heavily on employing a three-dimensional semi-infinite fluid element. The usual method for calculating the impedance matrix of this fluid hyper-element is dependent on the solution of a complex eigen-value problem for each frequency. In the present study, an efficient procedure is proposed which simplifies this procedure amazingly, and results in great computational time saving. Moreover, the accuracy of this technique is examined thoroughly and it is concluded that efficient procedure is incredibly accurate under all practical conditions.

An analytical-numerical procedure for cracking and time-dependent effects in continuous composite beams under service load

  • Chaudhary, Sandeep;Pendharkar, Umesh;Nagpal, A.K.
    • Steel and Composite Structures
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    • v.7 no.3
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    • pp.219-240
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    • 2007
  • An analytical-numerical procedure has been presented in this paper to take into account the nonlinear effects of concrete cracking and time-dependent effects of creep and shrinkage in the concrete portion of the continuous composite beams under service load. The procedure is analytical at the element level and numerical at the structural level. The cracked span length beam element consisting of uncracked zone in middle and cracked zones near the ends has been proposed to reduce the computational effort. The progressive nature of cracking of concrete has been taken into account by division of the time into a number of time intervals. Closed form expressions for stiffness matrix, load vector, crack lengths and mid-span deflection of the beam element have been presented in order to reduce the computational effort and bookkeeping. The procedure has been validated by comparison with the experimental and analytical results reported elsewhere and with FEM. The procedure can be readily extended for the analysis of composite building frames where saving in computational effort would be very considerable.

Efficient seismic analysis of multi-story buildings

  • Lee, Dong Guen;Kim, Hee Cheul
    • Structural Engineering and Mechanics
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    • v.4 no.5
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    • pp.497-511
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    • 1996
  • The equivalent static force procedure and the response spectrum analysis method are widely used for seismic analyses of multi-story buildings. The equivalent static force procedure is one of the most simple but less accurate method in predicting possible seismic response of a structure. The response spectrum analysis method provides more accurate results while it takes much longer computational time. In the response spectrum method, dynamic response of a multi-story building is obtained by combining modal responses through a proper procedure such as SRSS or CQC method. Since all of the analysis results are expressed in absolute values, structural engineers have difficulties to combine them with the results obtained from the static analysis. Design automation is interrupted at this stage because of the difficulty in the decision of the most critical design load. Pseudo-dynamic analysis method proposed in this study provides more accurate seismic analysis results than those of the equivalent static force procedure since the dynamic characteristics of a structure is considered. And the proposed method has an advantage in combination of the analysis results due to gravity loads and seismic loads since the direction of the forces can be considered.

An optimum design of on-bottom stability of offshore pipelines on soft clay

  • Yu, Su Young;Choi, Han Suk;Lee, Seung Keon;Do, Chang Ho;Kim, Do Kyun
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.5 no.4
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    • pp.598-613
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    • 2013
  • This paper deals with the dynamic effect of pipeline installation and embedment for the on-bottom stability design of offshore pipelines on soft clay. On-bottom stability analysis of offshore pipelines on soft clay by DNV-RP-F109 (DNV, 2010) results in very unreasonable pipe embedment and concrete coating thickness. Thus, a new procedure of the on-bottom stability analysis was established considering dynamic effects of pipeline installation and pipe-soil interaction at touchdown point (TDP). This analysis procedure is composed of three steps: global pipeline installation analysis, local analysis at TDP, modified on-bottom stability analysis using DNV-RP-F109. Data obtained from the dynamic pipeline installation analysis were utilized for the finite element analysis (FEA) of the pipeline embedment using the non-linear soil property. From the analysis results of the proposed procedure, an optimum design of on-bottom stability of offshore pipeline on soft clay can be achieved. This procedure and result will be useful to assess the on-bottom stability analysis of offshore pipelines on soft clay. The analysis results were justified by an offshore field inspection.

Feasibility of Computed Tomography Colonography as a Diagnostic Procedure in Colon Cancer Screening in India

  • Manjunath, Kanabagatte Nanjundappa;Gopalakrishna, Prabhu Karkala;Siddalingaswamy, Puttappa Chandrappa
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.13
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    • pp.5111-5116
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    • 2014
  • Computed Tomography Colonography (CTC) is a medical imaging technology used in identifying polyps and colon cancer masses in the large intestine. The technique has evolved a great deal since its invention and has become a routine diagnostic procedure in Western countries due to its non invasiveness and ease of use. The objective of our study was to explore the possibility of CTC application in Indian hospitals. This paper gives an overview of the procedure and its commercial viability. The explanation begins with the domain aspects from gastroenterologist perspective, the new way of thinking in polyp classification, the technical components of CTC procedure, and how engineering solutions have helped clinicians in solving the complexities involved in colon diagnosis. The colon cancer statistics in India and the results of single institution study we carried out with retrospective data is explained. By considering the increasing number of patients developing colon malignancies, the practicality of CTC in Indian hospitals is discussed. This paper does not reveal any technical aspects (algorithms) of engineering solutions implemented in CTC.

A Study on Improvement of Architectural Design Process on the Interface in Designing of Power Plant (발전플랜트 설계 인터페이스 중심의 건축설계절차 개선에 관한 연구)

  • Lee, Gang-Ok;Kim, Da-Hee
    • Journal of the Korean Society of Industry Convergence
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    • v.23 no.1
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    • pp.9-15
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    • 2020
  • The cooperation with other work types and designing procedure in plant industry and engineering showed clear differences from general construction industries. Current problems are that design's consistency is reduced because of the false system of interface and it ultimately causes frequency changes of design and delayed submission of final book. To solve the problems, the improvements of designing procedure were studied by focusing on the field of architectural designing and the range was limited from power plant construction industry to engineering designing field. If combining GA with the field of architectural designing and receiving data previously, it's possible to conduct expectable designing on small changes in the future, so it's expected to improve greatly cooperation with interface among the work types of power plant engineering received previously from the aspect of consistency. For the application of designing tool, a checklist, interim check will be conducted if progressed by list's division in the designing procedure, not book's completing period. In the interface among the designing work types, direct confirmation and revision must be conducted. In case of 3D modeling, the reflection of input data must be conducted from the basic designing so as to solve interferences intensively.

Analysis of R/C frames considering cracking effect and plastic hinge formation

  • Kara, Ilker Fatih;Ashour, Ashraf F.;Dundar, Cengiz
    • Structural Engineering and Mechanics
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    • v.63 no.5
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    • pp.669-681
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    • 2017
  • The design of reinforced concrete buildings must satisfy the serviceability stiffness criteria in terms of maximum lateral deflections and inter story drift in order to prevent both structural and non-structural damages. Consideration of plastic hinge formation is also important to obtain accurate failure mechanism and ultimate strength of reinforced concrete frames. In the present study, an iterative procedure has been developed for the analysis of reinforced concrete frames with cracked elements and consideration of plastic hinge formation. The ACI and probability-based effective stiffness models are used for the effective moment of inertia of cracked members. Shear deformation effect is also considered, and the variation of shear stiffness due to cracking is evaluated by reduced shear stiffness models available in the literature. The analytical procedure has been demonstrated through the application to three reinforced concrete frame examples available in the literature. It has been shown that the iterative analytical procedure can provide accurate and efficient predictions of deflections and ultimate strength of the frames studied under lateral and vertical loads. The proposed procedure is also efficient from the viewpoint of computational time and convergence rate. The developed technique was able to accurately predict the locations and sequential development of plastic hinges in frames. The results also show that shear deformation can contribute significantly to frame deflections.

Investigation on the thermal butt fusion performance of the buried high density polyethylene piping in nuclear power plant

  • Kim, Jong-Sung;Oh, Young-Jin;Choi, Sun-Woong;Jang, Changheui
    • Nuclear Engineering and Technology
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    • v.51 no.4
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    • pp.1142-1153
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    • 2019
  • This paper presents the effect of fusion procedure on the fusion performance of the thermal butt fusion in the safety class III buried HDPE piping per various tests performed, including high speed tensile impact, free bend, blunt notched tensile, notched creep, and PENT tests. The suitability of fusion joints and qualification procedures was evaluated by comparing test results from the base material and buttfusion joints. From the notched tensile test result, it was found that the fused joints have much lower toughness than the base material. It was also identified that the notched tensile test is more desirable than the high speed tensile impact and free bend tests presented in the ASME Code Case N-755-3 as a fusion qualification test method. In addition, with regard to the single low-pressure fusion joint performances, the procedure given by the ISO 21307 was determined to be better that the one specified in the Code Case N-755-3.

An Effective Procedure for Development of Industrial Safety Signs Corresponding to International Criteria (국제기준에 부합하는 효과적인 안전표지의 개발절차)

  • Lim, Hyeon-Kyo;Park, Young-Won;Lee, Joon-Won;Jung, Kwang-Tae
    • Journal of the Korean Society of Safety
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    • v.22 no.4
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    • pp.96-101
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    • 2007
  • Usually pictograms embedded in safety signs are such final means to transmit hazard information that the importance of them cannot be emphasized too much. Nevertheless, in Korea, few people are interested in safety signs and their functions so that evaluation of safety signs are seldom committed nor safety signs draw workers' attention to fulfill their functions. Therefore this research aimed to standardize the procedure for developing safety signs in order not only to give practical help to industrial workers but to match them international standards, and to develop a few examples through the suggested standard procedure. As results, a procedure for developing industrial safety signs was developed by combining both ANSI Z535.3 and ISO 9186 with a special emphasis on action inducibility as the former emphasized as well as comprehensibility as the latter suggested. According to test results with undergraduate students as well as industrial workers on a few signs developed through the suggested procedure, action inducibility was higher whereas confusion rate was lower than expected on one hand, and it could be concluded that the procedure would supply results that can be satisfied on the other hand.