• Title, Summary, Keyword: Structural Characteristic Analysis

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Criterion for judging seismic failure of suspen-domes based on strain energy density

  • Zhang, Ming;Parke, Gerry;Tian, Shixuan;Huang, Yanxia;Zhou, Guangchun
    • Earthquakes and Structures
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    • v.15 no.2
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    • pp.123-132
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    • 2018
  • In this paper the strain energy density (SED) model is used to analyze the seismic behavior of suspen-domes and a new criterion is established for judging the seismic failure based on a characteristic point in the SED model. Firstly, a nonlinear time-history response analysis was carried out using the finite-element package ANSYS for typical suspen-domes subjected to different ground motions. The seismic responses including nodal displacements, ratios of yielding members, strain energy density and structural maximum deformation energy were extracted corresponding to the increasing peak ground acceleration (A). Secondly, the SED sum ($I_d$) was calculated which revealed that the $I_d-A$ curve exhibited a relatively large change (called a characteristic point) at a certain value of A with a very small load increment after the structures entered the elastic-plastic state. Thirdly, a SED criterion is proposed to judge the seismic failure load based on the characteristic point. Subsequently, the case study verifies the characteristic point and the proposed SED criterion. Finally, this paper describes the unity and application of the SED criterion. The SED method may open a new way for structural appraisal and the SED criterion might give a unified criterion for predicting the failure loads of various structures subjected to dynamic loads.

Ground Deformation Analysis of Tunnel Excavation Based on the Ground Characteristic Line Concept (지반특성곡선 개념을 이용한 터널굴착 거동해석)

  • 손준익;정하익
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.118-125
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    • 1992
  • The ground deformation due to the tunnel excavation is dependent on various factors such as ground condition, geometry of the tunnel, excavation method, installation of support members, construction condition of each excavation stage, etc. And the distance from the facing effects significantly the stress conditions of the supported and unsupported ground due to the 3-dimensional structural nature of the excavated tunnel. The concept of ground characteristic line has been applied to properly consider the loading condition given by staged tunnel excavation so that the imaginary supporting pressure is applied against the surface of excavated ground. Discussions on the results of the performed finite element analysis were mainly made with respect to the ground settlement, tunnel displacement, earth pressure, stress mobilized in supporting members.

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Structural Characteristic Analysis of a High-precision Centerless Grinding Machine with a Concrete-filled Bed

  • Kim, Seok-Il;Cho, Jae-Wan
    • International Journal of Precision Engineering and Manufacturing
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    • v.7 no.4
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    • pp.34-39
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    • 2006
  • High-precision centerless grinding machines are emerging as a means of finishing the outer diameter grinding process required for ferrules, which are widely used as fiber optic connectors. In this study, a structural characteristic analysis and evaluation were carried out using a virtual prototype of a centerless grinding machine to realize systematic design technology and performance improvements required to manufacture ferrules. The prototype consisted of a concrete-filled bed, hydrostatic grinding wheel (GW) and regulating wheel (RW) spindle systems, a hydrostatic RW feed mechanism, a RW swivel mechanism, and on-machine GW and RW dressers. The loop stiffness values of the centerless grinding machine were estimated based on the relative displacements between the GW and RW caused by grinding forces. The simulated results illustrated that a concrete-filled bed considerably improved the structural stiffness and accuracy of a high-precision centerless grinding machine.

Structural Characteristic Analysis of a High-Precision Centerless Grinding Machine with Concrete-Filled Bed (콘크리트 층진 베드를 적용한 초정밀 무심 연삭기의 구조 해석)

  • Kim Seok Il;Cho Jae Wan
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.2
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    • pp.172-179
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    • 2005
  • A high-precision centerless grinding machine has been recognized as a core equipment performing the finish outer-diameter grinding process of ferrules which are widely used as fiber optic connectors. In this study, in order to realize the high-precision centerless grinding machine, the structural characteristic analysis and evaluation are carried out on the virtual prototype consisted of the steel bed, hydrostatic GW and RW spindle systems, hydrostatic RW feed mechanism, RW swivel mechanism, and on-machine GW and RW dressers. The loop stiffnesses of centerless grinding machine are estimated based on the relative deformations between GW and RW caused by the grinding forces. And the simulated results illustrate that the concrete-filled bed has the considerable effect on the improvement of the structural stiffness of centerless grinding machine.

Aseismic analysis for large underground structure (대형 지하구조물의 내진해석)

  • Choi, Seung-Ho;Pam, Inn-Joon;Kim, Sang-Hwan
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.11 no.2
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    • pp.163-174
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    • 2009
  • The large underground structure under earthquake is affected more by soil dynamic characteristic and volume of structure than by structural dynamic characteristic itself. Therefore, it is the purpose of research that the aseismic analysis for caverns including various aseismic analysis factors (rock quality-Q value, soil dynamic characteristic, shape ratio $&$ volume, underground structural dynamic characteristic, and aseismic level) are applied by using the numerical analysis program (SAUS; seismic analysis of underground structures). The result of research is stated that maximum strain, maximum moment, and maximum shear are not sensitive with respect to shape ratio. However those values are sensitive with respect to Q value, volume of underground structure and aseismic level. Based on the results of this research, the assessment for the influence factors of aseismic analysis for large underground structure could be possible.

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A Study on Structural Integrity and Dynamic Characteristic of Inertial Load Test Equipment for Performance Test of Railway Vehicle Propulsion Control System (철도차량 추진제어장치 성능시험을 위한 관성부하 시험설비의 구조안전성 및 동특성 평가 연구)

  • Jang, Hyung-Jin;Shin, Kwang-Bok;Lee, Sang-Hoon;Lee, Dae-Bong
    • Journal of the Korean Society for Railway
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    • v.13 no.4
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    • pp.363-370
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    • 2010
  • This paper describes the evaluation of structural integrity and dynamic characteristic of inertial load test equipments for performance test of railway vehicle propulsion control system. The propulsion control system of railway vehicle has to be confirmed of safety and reliability prior to its application. Therefore, inertial load test equipments were designed through theoretical equation for performance test of propulsion control system. The structural analysis of inertial load test equipments was conducted using Ansys v11.0 and the dynamic characteristic was evaluated using Adams. The results showed that the structural integrity of inertial load test equipment was satisfied with a safety factor of 10.2 on the bearing part under combined load. Also, the structural stability of flywheel according to dynamic simulation was secured by the maximum oscillation displacement within 0.83mm.

Non-linear Structural Analysis of Main Wing Spar of High Altitude Long Endurance UAV (고고도 장기체공무인기 주익 Spar 비선형 구조 해석)

  • Park, Sang-Wook;Shin, Jeong-Woo;Lee, Mu-Hyoung;Kim, Tae-Uk
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.23 no.1
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    • pp.24-29
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    • 2015
  • In order to increase endurance flight efficiency of long endurance electric powered UAV, main wing of UAV should have high aspect ratio and low structural weight. Since a spar which consists of thin and slender structure for weight reduction can cause catastrophic failure during the flight, it is important to develop verification method of structural integrity of the spar with the light weight design. In this paper, process of structural analysis using non-linear finite element method was introduced for the verification of structural integrity of the spar. The static strength test of the spar was conducted to identify structural characteristic under the static load. Then, the experimental result of the spar was compared to the analytical result from the non-linear finite element analysis. It was found that the developed process of structural analysis could predict well the non-linear structural behavior of the spar under ultimate load.

The Effects of the Structural Characteristics of Women's Jacket Fabrics for Spring.Summer on the Sensibility Image and Consumer Preference: The Comparison of Offline and Online (춘.하 여성 재킷용 소재의 구조적 특성이 감성이미지와 소비자 선호에 미치는 영향: 오프라인과 온라인의 비교를 중심으로)

  • Kim, Hee-Sook;Choi, Jong-Myung;Na, Mi-Hee
    • Journal of the Korean Home Economics Association
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    • v.49 no.1
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    • pp.121-133
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    • 2011
  • This research was designed to compare the subjective evaluation of texture image and preference between offline and online by structural characteristics of women' jacket fabrics for spring and summer. 78 participants evaluated the sensibility image and preference of various fabrics. The data were analysed by factor analysis, t-test, Pearson's productive correlation, regression, and multi dimensional scale. The results were as follows: Sensibility image factors of women' jacket fabrics were 'classic' 'sophisticated' 'natural' 'characteristic' and 'practical'. Between offline and online, sensibility images showed no differences. In sensibility images, 'classic'-'sophisticated', 'natural'-'practical', and 'practical'-'characteristic' images showed significant correlation. By analyzing the contribution of fabric structure on sensibility images, density affected on the 'classic' image offline and online. By the results of regression analysis, thickness, density and weave affected on the tactile preference. In sensibility images, 'classic', 'sophisticated' 'characteristic' images were the influencing factor. 'Sophisticated', 'natural', 'characteristic' and 'practical' images affected on the purchase preference.

An Evaluation of Structural Characteristics and Integrity for Rocket Motor Case according to Dome Types (돔 형상에 따른 연소관의 구조 특성 및 안전성 평가)

  • Ko, Hee-Young;Shin, Kwang-Bok;Kim, Won-Hoon;Koo, Song-Hoe
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • pp.257-262
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    • 2009
  • Elastic-Plastic structural analysis was performed to evaluate structural characteristic and integrity for rocket motor case of solid propulsion system. The structural analyses were compared and evaluated using the simplified 2-D axisymmetric model and 3-D full model for rocket motor case with torispherical dome type. And pre-tension load for bolt model was considered in structural analysis. The results of displacement and stress for the simplified 2-D axisymmetric model and 3-D full model were in an good agreement with each other. Therefore, the simplified 2-D axisymmetric model for rocket motor case was recommended to verify quickly the structural integrity and save the modeling and calculating time in initial design stage. Also, the structural characteristic and integrity for rocket motor case according to 5 dome types was evaluated to select the optimal dome shape.

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Modal Analysis of Curved Beam. (곡선보의 모우드 해석)

  • 김영문;유기표
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.349-354
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    • 2000
  • The modal analysis based on deformations is the method to drived dynamic responsed from superposition of natural frequency and mode shape. In order to free vibration analysis of the structures, Aluminum-made model is used in experiment. The dynamic characteristic of the structures are determined from acceleration measurements using impulse hammer. Experimenrt input and output signal are derive from impact hammer and the one accerometer. This paper present three methods for calculating the natural frequencies and mode shapes of the structure with theory value and finite element analysis, experiment. The results were good approximated about natural frequency and mode shape.

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