• Title/Summary/Keyword: Impact Analysis

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Exploratory Research on the Introduction of Family Impact Analysis (가족영향평가 도입방안 탐색연구)

  • Lee, Hyunah
    • Journal of the Korean Home Economics Association
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    • v.50 no.7
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    • pp.97-107
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    • 2012
  • The aim of this study is to suggest the introduction of family impact analysis. Family impact analysis is needed to evaluate family policies from the family perspective. This study deals with the definition of family impact analysis and the cases of other impact analysis, such as gender impact assessment and employment impact analysis. In addition, this study suggests the introduction of family impact analysis with evaluation methods, evaluation indicators, and evaluation processes. Evaluation methods are divided into self-assessment and specific-assessment. Evaluation indicators need to be developed based on the family strength. This research also suggests the securing of family time as a basic assessment indicator. The evaluation processes consist of object selection, assessment, evaluation report, and policy improvement. Finally, this study suggests that family impact analysis is a strong strategy for promoting family-friendly policies. In order to introduce family impact analysis in a more systematic manner, further studies on the standards of assessment, formation of research institutions, and the legislative system will be necessary.

Transient stress analysis of tracked vehicle structures under recoil impact load (주퇴충격하중을 받는 궤도차량 구조물의 천이응력해석)

  • 이영신;김용환;김영완;김동수;성낙훈
    • Journal of the korean Society of Automotive Engineers
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    • v.15 no.3
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    • pp.111-119
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    • 1993
  • In this study, the transient impact structural stress analysis of tracked vehicle structures under recoil impact load is investigated. ANSYS, ABAQUS Code are used for modelling and analytical procedures. The highest maximum Tresca stress occurs on race ring portion and its stress level is (.sigma.$_{T}$)$_{max}$ =20-40kgf/m $m^{2}$. The second highest stress occurs on upper plate of chassis and down plate of turret. The maximum stress level increases with loading direction and elevation angle. The results from liner static load analysis are very much different with impact analysis. Therefore, the practical solutions of structures under impact load can be obtained by only nonlinear transient impact analysis. The impact stress analysis of the steel vehicle structures is conducted. The maximum stress level is less than (.sigma.$_T/)$_{max}$m $m^{2}$. So, the design concept of steel structures can be adapted for new alternatives.s.s.s..s.

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Low-Velocity Impact Response Analysis of Composite Laminates Considering Higher Order Shear Deformation and Large Deflection (고차전단변형과 대처짐을 고려한 복합적층판의 저속충격거동 해석)

  • 최익현;홍창선
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.12
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    • pp.2982-2994
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    • 1993
  • Low-velocity impact responses of composite laminates are investigated using the finite element method based on various theories. In two-dimensional nonlinear analysis, a displacement field considering higher order shear deformation and large deflection of the laminate is assumed and a finite element formulation is developed using a C$^{o}$-continuous 9-node plate element. Also, three-dimensional linear analysis based on the infinitesimal strain-displacement assumptions is performed using 8-node brick elements with incompatible modes. A modified Hertzian contact law is incorporated into the finite element program to evaluate the impact force. In the time integration, the Newmark constant acceleration algorithm is used in conjuction with successive iterations within each time step. Numerical results from static analysis as well as the impact response analysis are presented including impact force histories, deflections, strains in the laminate. Impact responses according to two typical low-velocity impact conditions are compared each other.

Change Impact Analysis in Engineering Design Process (공학 설계 프로세스에서 설계 변경 영향 해석)

  • 정태형;박승현
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.1
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    • pp.151-158
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    • 2003
  • Design changes frequently occur while design activities are performed. If the impact of design changes is estimated, design efficiency can be improved. But, the types of design changes are various and they can affect other design parts. Hence, it is difficult to deal with design changes directly. The purpose of this research is to develop systematic algorithms for change propagation tracing and change impact analysis, and then to implement a change impact analysis system. We have selected a process-based design and a design environment which is composed of design parameters and constraints. The algorithm for change propagation tracing tracks the change propagation of design parameters and finds design parameters, constraints and tasks which are probably changed. In the algorithm for change impact analysis, a change impact value is calculated from the list of changeable tasks. These two algorithms have been implemented into change impact analysis system (CIAS). CIAS has been applied to the redesign of 2 stage gear drives. CIAS can improve the efficiency of design activities. If there are many alternatives for a design change at the redesign step, designers can calculate the change impact value of each alternative and perform design change activities in the direction of minimizing design change impact.

A Study on Low Velocity Impact Characteristics of DP 780 High Strength Steel Sheet with Thickness of 1.7 mm on the Free Boundary Condition Using Three-Dimensional Finite Element Analysis (3 차원 유한요소해석을 이용한 자유경계조건에서의 두께 1.7 mm DP780 고강도 강판의 저 속 충격 특성 분석)

  • Ahn, Dong-Gyu;Nam, Gyung-Heum;Seong, Dae-Yong;Yang, Dong-Yol;Lim, Ji-Ho
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.11
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    • pp.46-56
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    • 2010
  • The present research works investigated into the low velocity impact characteristics of DP 780 high strength steel sheet with 1.7 mm in thickness subjected to free boundary condition using three-dimensional finite element analysis. Finite element analysis was carried out via ABAQUS explicit code. Hyper-elastic model and the damping factor were introduced to improve an accuracy of the FE analysis. An appropriate FE model was obtained via the comparison of the results of the FE analyses and those of the impact tests. The influence of the impact energy and nose diameter of the impact head on the force-deflection curves, impact time, absorption characteristics of the impact energy, deformation behaviours, and stress-strain distributions was quantitatively examined using the results of FE analysis. The results of the FE analysis showed that the absorption rate of impact energy lies in the range of the 70.7-77.5 %. In addition, it was noted that the absorption rate of impact energy decreases when the impact energy increases and the nose diameter of the impact head decreases. The local deformation of the impacted region was rapidly increased when the impact energy was larger than 76.2 J and the nose diameter was 20 mm. A critical impact energy, which occur the instability of the DP780, was estimated using the relationship between the plastic strain and the impact energy. Finally, characteristics of the plastic energy dissipation and the strain energy density were discussed.

A study on the impact pulse analysis with various shapes and materials of impactor (충격자의 형상 및 재질변화에 따른 펄스형성에 관한 연구)

  • Lee, Yeong-Sin;Kim, Dong-Jin;Gang, Geun-Hui;O, Jong-Su
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.22 no.1
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    • pp.52-63
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    • 1998
  • The impact programmer for impact test was designed and the impact analysis was conducted. The effects of the material and geometric parameters on the impact force and pulse shape were investigated. The impact characteristics were examined by experimental and finite element method. The impact test was conducted with free drop impact tester. The ABAQUS/Explicit 5.5 version was used for finite element analysis. The geometric parameters of the conical and dome type impact programmer were analyzed. The polyurethane impact programmers were fabricated and tested. The effects of the hardness and thickness of the impact programmer were studied. The peak acceleration and time duration of impact programmer have close correlation with the hardness, impact energy and thickness of the impactor. The experiment was good agreement with analytical predictions. The impact pulse shape generated with polyurethane impact programmer was half sine shape. The maximum impact force was proportional to impact energy. The impact acceleration was decreased with thickness of impact programmer. The maximum impact time duration level was about 2 msec.

Development of Estimation Technique of Impact Noise caused by Vibration (충격 시 진동에 의한 방사 소음의 예측 기법에 관한 연구)

  • Jung, Bong-Bu;Oh, Jin-Taek;Park, Hyun-Chul
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.911-916
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    • 2008
  • Impact noise caused by the collision of bodies is difficult to estimate because of the complexity of impact phenomenon. In this study, impact noise is estimated using two different methods when the noise is caused by the vibration due to impact. First, impact noise is analyzed using impact analysis and boundary element analysis. Second, modal expansion technique is applied to the estimation of impact noise. Experiment is carried out to validate the analysis results.

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Cross Impact Analysis Using Goal Programming (Goal Programming을 이용한 상호영향도 분석)

  • 김연민;이진주
    • Journal of the Korean Operations Research and Management Science Society
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    • v.6 no.1
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    • pp.15-23
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    • 1981
  • This paper deals with cross impact analysis for technology assessment. The focus of the paper is to develop new technique of cross impact matrix using goal programming method. In this study, the idea of cross impact analysis based on scenario generation method especially SMIC-74 (2) is expanded. Critical literature review on SMIC-74 is presented to discuss the mathematical rationale of consistent probability in cross impact analysis. A new model of cross impact analysis using goal programming to overcome the shortcomings of the scenario generation technique especially SMIC-74 is developed. This new technique is also applied to the assessment of the air pollution problems in Seoul Metropolitan area in Korea. The results of analysis give us following findings 1) Cross impact analysis using goal programming produce more meaningful solutions comparing to those of SMIC-74 2) Theoretical rationale of the objective function in the newly developed technique is more appropriate than that of SMIC-74.

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A study on the impact prediction in environmental impact statement (환경영향평가서 영향예측에 대한 연구)

  • 이영경
    • Journal of the Korean Institute of Landscape Architecture
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    • v.25 no.3
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    • pp.89-100
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    • 1997
  • The purpose of this paper was to analyze the content of impact prediction in EISS, in order to find the degree of the acuracy of impact prediction . 30 EISS were selected as analysis objects through variance miximization strategy. Content analysis of the selected EISS was performed by 5 analysis items, such as quantification of measurement, range of impact area, time frame of impact, likelihood of impact, and explict characterization of impact significance. The results showed that the accuracy investigated by the 5 items was very low. In conclusion, 5 suggestions were proposed in order to improve the credibility of EIS as a scientific report. The 5 suggestions were : 1) impact prediction should be described by quantitative measurement; 2) In establishing the time frame of the impact and the referent populatioin influenced by the impact, the characteristics of the proposed action should be carefully considerd; 3) the significance of the predicted impact should be quantitatively described; 4) specific description should also be used in the likelihood or the probability of the predicted impact in a real world; 5) equal emphasis should be put on the three environment, including natural and social as well as living environment.

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Calculation of Impact Force between Teeth of Upper and Lower Jaw-Bones while Masticating for Dental Implant System Design (임프란트설계를 위한 저작시 상.하악골치아 사이의 충격력 계산)

  • 권영주
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.425-428
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    • 2000
  • In this paper the impact force which occurs on each tooth of jaw-bones while masticating is calculated through the rigid body dynamic analysis. This analysis is done by ADAMS. The impact force calculated in this paper is required for the structural stress analysis of implant system which is needed for the implant system design. The analysis results show that the impact time decreases as the impact force increases, the largest impact force occurs on the front tooth and the impact force is almost normal to the tooth surface together with slight tangential force.

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