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Development of a Static and Dynamic Analysis System for Motor-Integrated High-Speed Spindle Systems Using Timoshenko Theory and Finite Element Method (Timoshenko 이론과 유한요소법을 이용한 모터내장형 고속주축계의 정특성/동특성 해석시스템 개발)

  • 이용희;김석일;김태형;이재윤
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.8
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    • pp.11-16
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    • 1998
  • Recently, the motor-integrated spindle systems have been used to simplify the machine tool structure, to improve the motion flexibility of machine tool, and to perform the high-speed machining. In this study, a static and dynamic analysis system for motor-integrated high-speed spindle systems is developed based on Timoshenko theory, finite element method and windows programming techniques. Since the system has various analysis modules related to static deformation analysis, modal analysis, frequency response analysis, unbalance response analysis and so on, it is useful in performing systematically the design and evaluation processes of motor-integrated high-speed spindle systems under windows GUI environment.

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A study of data acquisition system of defense analysis & evaluation by systems engineering process (시스템엔지니어링 프로세스에 의한 국방 분석평가자료 수집체계 연구)

  • Choe, Sun-Hwang;Min, Seong-Gi
    • 시스템엔지니어링워크숍
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    • pp.135-140
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    • 2004
  • Defense analysis & evaluation includes menace analysis, validation analysis, problem analysis, scientific technical analysis, technical trad-off analysis, alternative analysis, cost analysis, etc. Reliable related data is required to perform these analysis activities efficiently. but in case of these defense analysis & evaluation data acquisition system, the data is insufficient and scattered about each organization. the data of database system is also not utilized sufficiently. abroad technical data is also low level data such as catalog or military officer's collection. therefore, this paper propose defense analysis & evaluation data acquisition system by systems engineering process. we also propose construction method of data acquisition system.

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A study of data acquisition system of defense analysis & evaluation by systems engineering process (시스템엔지니어링 프로세스에 의한 국방 분석평가자료 수집체계 연구)

  • Min, Sungki;Choi, Soonhwang
    • Journal of the Korea Society of Systems Engineering
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    • v.1 no.2
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    • pp.69-76
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    • 2005
  • Defense analysis & evaluation includes menace analysis, validation analysis, problem analysis, scientific technical analysis, technical trade-off analysis, alternative analysis, cost analysis, etc. Reliable related data is required to perform these analysis activities efficiently. but in case of these defense analysis & evaluation data acquisition system, the data is insufficient and scattered about each organization. The data of database system is also not utilized sufficiently. Abroad technical data is also low level data such as catalog or military officer's collection. Therefore, this paper propose defense analysis & evaluation data acquisition system by systems engineering process. we also propose construction method of data acquisition system.

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Structural Analysis on the Leaflet Motion Interacted with Blood Flow for Thickness Minimization Design of a Bileaflet Mechanical Heart Valve (기계식 인공심장판막의 경량화 구조설계를 위한 혈액유동과 상호작용하는 판막거동의 구조역학적 특성연구)

  • 권영주;방혜철;김창녕
    • Korean Journal of Computational Design and Engineering
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    • v.6 no.1
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    • pp.59-68
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    • 2001
  • This paper investigates the structural analysis and design of mechanical heart valve through the numerical analysis methodology. In a numerical analysis methodology application to the thickness minimization structural design of mechanical heart valve, fluid analysis is performed for the blood flow through a bileaflet mechanical heart valve. Simultaneously the kinetodynamic analysis is carried out to obtain the appropriate structural condition for the structural analysis. Thereafter the structural static analysis is also carried out to confirm the thickness minimization structural condition(minimum thickness shape of leaflet).

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Nonlinear finite element analysis of reinforced concrete structures subjected to transient thermal loads

  • Zhou, C.E.;Vecchio, F.J.
    • Computers and Concrete
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    • v.2 no.6
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    • pp.455-479
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    • 2005
  • This paper describes a 2D nonlinear finite element analysis (NLFEA) platform that combines heat flow analysis with realistic analysis of cracked reinforced concrete structures. The behavior models included in the structural analysis are mainly based on the Modified Compression Field Theory and the Distributed Stress Field Model. The heat flow analysis takes into account time-varying thermal loads and temperature-dependent material properties. The capability of 2D nonlinear transient thermal analysis is then implemented into a nonlinear finite element analysis program VecTor2(C) for 2D reinforced concrete membranes. Analyses of four numerical examples are performed using VecTor2, and results obtained indicate that the suggested nonlinear finite element analysis procedure is capable of modeling the complete response of a concrete structure to thermal and mechanical loads.

RISK ANALYSIS OF FOREIGN DIRECT INVESTMENTS IN INNOVATIVE PROJECTS: CASE OF UZBEKISTAN

  • Lutfullaevich, Yoziev Golibjon
    • Asia Pacific Journal of Business Review
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    • v.5 no.1
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    • pp.11-19
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    • 2020
  • This study is a review on Risk analysis of foreign direct investments in innovative projects of Uzbekistan. The study will examine SWOT and PESTL analysis as an effective situation analysis tool which plays an important role in the fields of management, marketing, and in any fields of requiring strategic planning. SWOT is an analysis method used to evaluate the 'strengths', 'weaknesses', 'opportunities', 'threats' and PESTL is an analysis tool used for measuring the 'political', 'economical', 'social', 'technological' and 'low' risks involved in a various sphere of economy. In this study, firstly the essence of SWOT and PESTL analysis is explained, secondly the components of SWOT and PESTL analysis is examined. The paper includes risk analysis for further investigation to innovation sector of Uzbekistan economy.

The Analysis of View and Daylights for the Design of Public Housing Complexes Using a Residential Environment Analysis System Integrated into a CAD System (주거환경분석시스템의 CAD 시스템 통합을 통한 공동주택단지설계 시 일조 및 조망분석에 관한 연구)

  • Park, Soo-Hoon;Ryu, Jeong-Won
    • Korean Journal of Computational Design and Engineering
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    • v.12 no.2
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    • pp.137-145
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    • 2007
  • This paper concerns about residential environment analysis program implementation for design and analysis on public housing complexes such that view and daylight analysis processes are automated and integrated into existing design routine to achieve better design efficiency. Considering the architectural design trends this paper chooses ArchiCAD as a platform for a CAD system, which contains the concepts such as integrated object-oriented CAD, virtual building and BIM. Residential environment analysis system consists of three components. The first component is the 3D modeling part defining 3D form information for external geographic contour models, site models and interior/exterior of apartment buildings. The second is the parametric library part handling the design parameters for view and daylight analysis. The last is the user interface for the input/output and integration of data for the environment analysis. Daylight analysis shows rendered images as well as results of daylight reports and grades per time and performs the calculations for floor shadow. It separates the site-only analysis from the analysis of site and exterior environmental parameters. View analysis considers horizontal and vertical view angles to produce view image from each unit and uses the bitmap analysis method to determine opening ratio, scenery ratio and void ratio. We could expect better performance and precision from this residential environment analysis system than the existing 2D drawing based view and daylight analysis methods and overcome the existing one-way flow of design information from 3D form to analysis reports so that site design modifications are automatically reflected on analysis results. Each part is developed in a module so that further integration and extension into other related estimation and construction management systems are made possible.

A Study on the Strength Evaluation Method of Plate Structures with Penetration-holes (관통구를 갖는 판구조물의 강도평가 방법에 관한 연구)

  • Kim, Ul-Nyeon;Jang, Jun-Tae
    • Journal of the Society of Naval Architects of Korea
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    • v.54 no.6
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    • pp.476-484
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    • 2017
  • The purpose of this paper is to verify the structural integrity of a region with numerous penetration-holes in offshore structures such as semi-submersible rig and FPSO. In order to effectively check the yielding and buckling strength of plate members with penetration-holes, a screening analysis program was developed with the FE analysis tool to generate fine meshed model using the theoretical and analysis methods. When a hole is appeared in the plate structure members, the flow of stress is altered such that concentrations of stress form near the hole. Stress concentrations are of concern during both preliminary and detail design and need to be addressed from the perspectives of strength. To configure the geometrical shape, very fine meshed FE analysis is needed as the most accurate method. However, this method is practically impossible to apply for the strength verifications for all perforated plates. In this paper, screening analysis method was introduced to reduce analysis tasks prior to detailed FE analysis. This method is applied to not only the peak stress calculation combined stress concentration factor with nominal stress but also nominal equivalent stress calculation considering cutout effects. The areas investigated by very fine meshed analysis were to be chosen through screening analysis without any reinforcements for penetration-holes. If screening analysis results did not satisfy the acceptance criteria, direct FE analysis method as the 2nd step approach were applied with one of the coarse meshed model considering hole or with the very fine meshed model considering the hole shape and size. In order to effectively perform the local fine meshed analysis, automatic model generating program was developed based on the MSC/PATRAN which is pre-post FE analysis program. Buckling strength was also evaluated by Common Structure Rule (CSR) adopted by IACS as the stress obtained from very fine meshed FE analysis. Due to development of the screening analysis program and automatic FE modeling program, it was able to reduce the design periods and structural analysis costs.

Development of Nonlinear Static Design Sensitivity Analysis Based ANSYS (ANSYS 비선형 정적설계민감도해석 외부모듈 개발)

  • Choi, Byung-Nam;Jung, Jae-Jun;Yoo, Jung-Hoon;Lee, Tae-Hee
    • Proceedings of the KSME Conference
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    • pp.543-547
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    • 2001
  • CAE has been settled down to an indispensable tool for the simulation of a mechanical system according to the development of computer-aided analysis rapidly. Particularly finite element programs have advanced to the one of most valuable things in the filed of CAE due to the remarkable progress in the implementation. But since this analysis tool mostly provides the result of the analysis, it cannot satisfy designers who are seeking for information to improve their designs. Therefore, design sensitivity analysis or optimization module has been incorporated into commercial FEA programs to satisfy the desire of designers since 1990s. Design sensitivity analysis is to compute the rate of change of response with respected to design variable. Design sensitivity analysis is classfied into static design sensitivity analysis, Eigenvalue design sensitivity analysis and dynamic design sensitivity analysis. In this research, it will be presented to nonlinear static design sensitivity analysis formulation and nonlinear static design sensitivity analysis external module based ANSYS have been developed and illustrated an example to verify the developed module.

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A Study on Methodology for Automated Contingency and Remedial Action Analysis based on Practical Approach: Development of Automated Scheduled Outage Analysis Tool (실용적 접근 기반의 전력계통 해석 프로그램 상정고장, 해소방안 자동화 기법: 휴전검토 자동화 툴 개발)

  • Song, Jiyoung;Ko, Baekkyung;Shin, Jeonghoon;Han, Sangwook;Nam, Suchul;Lee, Jaegul;Kim, Taekyun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.9
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    • pp.1171-1179
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    • 2014
  • ISO(Independent System Operator) or TSO(Transmission System Operator) use power system analysis program to simulate contingency analysis and remedial actions to operate power system stably. Generally, power system analysis program provides automated analysis functions(or modules) to deal with wide area power system. However, because of missed contingency cases, automated contingency analysis has no practical use or has limitation. And in case of remedial action, it doesn't support automated function or takes a lot of times to study, because of simulation in manual for each cases. This paper suggests that new relation with buses and transmission line properties of power system DB used for power system analysis program to simulate automated contingency including all contingency cases needed in the field without missed cases. And it proposes automated remedial action scheme based on practical approach analysis to alleviate overloading or voltage problems. Finally it deals with automated contingency/remedial action analysis(automated scheduled outage) program which is developed by KEPCO and its performance and proposed schemes are proven by case study for real Korean power system data.