• 제목/요약/키워드: IMPACT

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주거지 개발사업에 대한 건강영향평가 사례 연구 (A Case Study on the Health Impact Assessment of Residential Development Projects)

  • 신문식;동종인;하종식
    • 환경영향평가
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    • 제29권5호
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    • pp.391-402
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    • 2020
  • 국내 법적 근거를 가진 건강영향평가(Health Impact Assessment)는 환경영향평가 항목 중 위생공중보건 항목에서 작성 수행되고 있다. 택지개발 등 주거지 개발사업들은 「환경보건법」 제13조에 따른 건강 영향평가 대상사업은 아니다. 하지만 환경영향평가협의회 단계에서 인근 산업단지 등 오염원에서 배출되는 물질 중 건강영향평가 대상물질을 확인하여 위해도(발암·비발암 포함)를 산정하여 제시하라는 심의내용에 근거하여 부분적인 건강영향평가로 수행하고 있다. 주거지 개발사업은 특정대기유해물질 등 오염물질 배출시설 계획이 없지만 주변 산업단지와 같은 대기오염 발생원에서 배출되는 오염물질에 의해 향후 입주하는 계획지구 주민들에게 건강영향을 미칠 수가 있다. 본 연구에서는 실제 도시개발사업 사례를 분석하여 미래에 입주하는 계획지구 입주민들에게 미치는 영향을 검토하고자 하였다. 미래에 영향 검토 시 주변지역에 대한 문헌을 통한 예측 case1, 대기확산모델(AERMOD)을 이용한 발암성물질 노출농도예측과 기여도 분석 case2를 하였다. 본 연구를 통해 계획지구 인근 산업단지 등의 오염원에 대한 수용체를 고려한 건강영향평가 방법으로는 현황조사와 대기확산모델(AERMOD)을 이용한 노출농도예측 및 기여도분석을 상호 보완적으로 적용하여 평가하는 것이 효용성이 높은 것으로 판단되었다.

자동차용 도어 모듈의 측면 충돌특성에 관한 실험적 연구 (Experimental Study on Side Impact Characteristics for Automotives Door Module)

  • 전성진;김민호;이규현;이문용
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2009년도 추계학술대회 논문집
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    • pp.318-318
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    • 2009
  • The door stiffness is one of the important factors side impact. Generally, the researches have been conducted on the assembled door module. This study is to analysis the side impact characteristics for automotives door module. The impact characteristics have been determined by door module side impact test machine. To determine the initial, intermediate and peak crush resistances use the plot of load versus displacement and obtain the integral of the applied load with respect to the crush distances specified below for each door tested. The initial crush resistance is the average force required to deform the door through the initial 6 inches of crush. The intermediate crush resistance is the average force required to deform the door through the initial 12 inches of crush. The peak crush resistance will be directly obtained from the plot of load versus displacement since it is the largest force required to deform the door through the entire 18 inches crush distance. The data are used to determine if a specific vehicle or item of automotives equipment meets the minimum performance requirements of the subject Federal Motor Vehicle Safety Standard(FMVSS). FMVSS Static 214, Side impact protection, specifies performance requirements for protection of occupants in side impact crashes.

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Response of triceratops to impact forces: numerical investigations

  • Chandrasekaran, Srinivasan;Nagavinothini, R.
    • Ocean Systems Engineering
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    • 제9권4호
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    • pp.349-368
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    • 2019
  • Triceratops is one of the new generations of offshore compliant platforms suitable for ultra-deepwater applications. Apart from environmental loads, the offshore structures are also susceptible to accidental loads. Due to the increase in the risk of collision between ships and offshore platforms, the accurate prediction of structural response under impact loads becomes necessary. This paper presents the numerical investigations of the impact response of the buoyant leg of triceratops usually designed as an orthogonally stiffened cylindrical shell with stringers and ring frames. The impact analysis of buoyant leg with a rectangularly shaped indenter is carried out using ANSYS explicit analysis solver under different impact load cases. The results show that the shell deformation increases with the increase in impact load, and the ring stiffeners hinder the shell damage from spreading in the longitudinal direction. The response of triceratops is then obtained through hydrodynamic response analysis carried out using ANSYS AQWA. From the results, it is observed that the impact load on single buoyant leg causes periodic vibration in the deck in the surge and pitch degrees of freedom. Since the impact response of the structure is highly affected by the geometric and material properties, numerical studies are also carried out by varying the strain rate, and the location of the indenter and the results are discussed.

ATB 소프트웨어를 이용한 측면충돌시 승랙거동해석 모델링의 확립 및 분석 (Establishment of an Occupant Analysis modeling for Automobile Side Impact Using ATB Software)

  • 임재문;최중원;박경진
    • 한국자동차공학회논문집
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    • 제4권6호
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    • pp.85-96
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    • 1996
  • Most protection systems such as seat belts and airbags are not effective means for side structure. There has been significant effort in the automobile industries in seeking other protective methods, such as stiffer structure and padding on the door inner panel. Therefore, a car-to-car side impact model has been developed using ATB occupant simulation program and validated for test data of the vehicle. Compared to the existing side impact models, the developed model has a more detailed vehicle side structure representation for the more realistic impact response of the door. This model include impact bar which effectively increases the side structure stiffness without reduction of space between the occupant and the door and padding for absorbing impact energy. The established model is applied to a 4-door vehicle. The parameter study indicated that a stiffer impact bar would reduce both the acceleration-based criteria, such as thoracic trauma index: TTI(d), and deformation-based criteria, such as viscous criterion(VC). Padding on the door inner panel would reduce TTI(d) while VC gives the opposite indication in a specified thickness range. For a 4-door vehicle, the stiffness enhancement of B-pillar is more beneficial than that of A-pillar for occupant injury severity indices.

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한국의 EIA 자료와 그의 활용 (Data for EIA and Its Presentation in Korea)

  • 이현영
    • 환경영향평가
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    • 제2권2호
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    • pp.73-83
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    • 1993
  • Increasing concern for the environment in Korea has led to the demand that major policies and large-scale development projects be subjected to detailed impact assessment. This paper reports on the state of data related to the prediction of the environmental impact (EIA) to emphasize the importance of data quality. Environmental impact statements (EIS) consulted with the Ministry of Environment of Korea were analyzed from 1981 through 1992. Many of assessors used existing data and collected supplementary data from field survey. Most of the results of EIA are presented directly or summarized on maps and as graphics. For the national purpose, large source of quality-controlled data such as atmospheric data have been developed, However, there are the deficiency in data to analyze the impact of human activity, and data gaps and incompatibilities among systems. Consequently, the development of data bank systems including computer database and remotely-sensed satellite data is required to improve the quality of data which are relevant to EIA. The data bank system should be organized meaningfully in minimum time with a least cost, and measurement standards must be made explicit. Geographical information systems (GIS) are applicable to the graphic presentation or to the impact prediction model.

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충격손상 복합재료의 피로수명에 대한 통계적 해석 연구 (Probabilistic Approach for Fatigue Life of Composite Materials with Impact-Induced Damage)

  • 강기원
    • 한국산학기술학회논문지
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    • 제11권9호
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    • pp.3148-3154
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    • 2010
  • 본 논문에서는 충격손상 복합재료의 피로수명 저하 특성과 이의 변동성을 통계적으로 분석하였다. 충격손상 복합재료의 잔류강도는 2모수 Weibull 분포에 잘 적합되었으며 충격에너지의 증가에 따라 잔류강도의 변동성은 감소 하였다. 복합재료의 피로수명은 충격손상에 의하여 크게 저하되었으며 또한 이의 피로수명에 대한 충격손상의 영향은 작용 응력진폭에 따라 변화함을 알 수 있었다. 또한 2모수 Weibull 분포를 이용하여 충격손상 복합재료의 피로수명의 변동성을 추정하였으며 충격에너지의 증강 및 응력진폭의 감소에 따라 피로수명의 변동성은 점차 감소하였다.

다중충돌 피닝잔류응력 평가를 위한 소성숏이 포함된 3차원 유한요소해석 모델 (A 3D FEA Model with Plastic Shots for Evaluation of Peening Residual Stress due to Multi-Impacts)

  • 김태형;이형일
    • 대한기계학회논문집A
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    • 제32권8호
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    • pp.642-653
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    • 2008
  • In this paper, we propose a 3-D finite element (FE) analysis model with combined physical behavior and kinematical impact factors for evaluation of residual stress in multi-impact shot peening. The FE model considers both physical behavior of material and characteristics of kinematical impact. The physical parameters include elastic-plastic FE modeling of shot ball, material damping coefficient, dynamic friction coefficient. The kinematical parameters include impact velocity and diameter of shot ball. Multi-impact FE model consists of 3-D symmetry-cell. We can describe a certain repeated area of peened specimen under equibiaxial residual stress by the cell. With the cell model, we investigate the FE peening coverage, dependency on the impact sequence, effect of repeated cycle. The proposed FE model provides converged and unique solution of surface stress, maximum compressive residual stress and deformation depth at four impact positions. Further, in contrast to the rigid and elastic shots, plastically deformable shot produces residual stresses closer to experimental solutions by X-ray diffraction. Consequently, it is confirmed that the FE model with peening factors and plastic shot is valid for multi-shot peening analyses.

Experimental Study on Impact Loads Acting on Free-falling Modified Wigley

  • Hong, Sa-Young;Kim, Young-Shik;Kyoung, Jo-Hyun;Hong, Seok-Won;Kim, Yong-Hwan
    • International Journal of Ocean System Engineering
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    • 제2권3호
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    • pp.151-159
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    • 2012
  • The characteristics of an impact load and pressure were experimentally investigated. Drop tests were carried out using a modified Wigley with CB = 0.56. The vertical force, pressures, and vertical accelerations were measured. A 6-component load cell was used to measure the forces, piezo-electric sensors were used to capture the impact pressure, and strain-gauge type accelerometers were used to measure the vertical accelerations. A 50-kHz sampling rate was applied to capture the peak values. The repeatability of the measured data was confirmed and the basic characteristics of the impact load and pressure such as the linearity to the falling height were observed for all of the measurements. A simple formula was derived to extract the physical impact load from the measured force based on a simple mass-sensor-mass diagram, which was validated by comparing impact forces with existing data using the mathematical model of Faltinsen and Chezhian (2005). The effects of the elasticity of the model and change in acceleration during the water entry were investigated. It is interesting to observe that the impact loads occurred and reached peak values at the same time duration after water entry for all drop heights.

CFRP 적층판의 충격손상이 잔류 굽힘 피로강도에 미치는 영향 (Influence of Residual Bending Fatigue Strength on Impact Damage of CFRP Composites)

  • 양용준;양인영
    • 한국안전학회지
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    • 제30권3호
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    • pp.7-12
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    • 2015
  • CFRP composites are used as primary structural members in various industrial fields because their specific strength and specific stiffness are excellent in comparison to conventional metals. Their usage is expanding to high added-value industrial fields because they are more than 50% lighter than metals, and have excellent heat resistance and wear resistance. However, when CFRP composites suffer impact damage, destruction of fiber and interface delamination occur. This causes an unexpected deterioration of strength, and for this reason it is very difficult to ensure the reliability of the excellent mechanical properties. Therefore, for the destruction mechanism in bending with impact damage, this study investigated the reinforcement data regarding various external loads by identifying the consequential strength deterioration. Specimens were damaged by impact with a steel ball propelled by air pressure. Decrease in bending strength caused by the tension and compression of the impact side, and depending on the lamination direction of fiber and interface inside the specimen. From the bending test it was found that the bending strength reduced when the impact energy increased. Especially in the case of compression on the impact side, as tensile stress occurred at the damage starting point, causing rapid failure and a substantially reduced failure strength.

A CFD Study of Roadside Barrier Impact on the Dispersion of Road Air Pollution

  • Jeong, Sang Jin
    • Asian Journal of Atmospheric Environment
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    • 제9권1호
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    • pp.22-30
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    • 2015
  • This study evaluated road shape and roadside barrier impact on near-road air pollution dispersion using FLUENT computational fluid dynamics (CFD) model. Simulated road shapes are three types, namely at-grade, depressed, and filled road. The realizable k-${\varepsilon}$ model in FLUENT CFD code was used to simulate the flow and dispersion around road. The selected concentration profile results were compared with the wind tunnel experiments. The overall concentration profile results show good agreement with the wind tunnel results. The results showed that noise barriers, which positioned around the at-grade road, decrease the horizontal impact distance (In this study, the impact distance was defined as the distance from road surface origin coordinate to the position whose mass fraction is 0.1.) lower 0.33~0.65 times and change the vertical air pollution impact distance larger 2.0~2.27 times than those of no barrier case. In case of filled road, noise barriers decrease the horizontal impact distance lower 0.24~0.65 times and change the vertical air pollution impact distance larger 3.33~3.55 times than those of no barrier case. The depressed road increase 1.53~1.68 times the vertical air pollution impact distance. It contributes the decrease of horizontal air pollution impact distance 0.32~0.60 times compare with no barrier case.