• 제목/요약/키워드: fire behavior

검색결과 594건 처리시간 0.026초

횡변형 방지 상세 유무 및 스트럿 형상에 따른 강재댐퍼의 성능 비교 (Performance Comparison of Steel Dampers with or without Lateral Deformation Prevention Details and Strut Shapes)

  • 이현호
    • 한국구조물진단유지관리공학회 논문집
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    • 제26권5호
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    • pp.66-73
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    • 2022
  • 본 연구에서는 록킹 거동을 하는 강재댐퍼에 대한 기존 연구결과를 근간으로 스트럿 높이가 동일하고 단면적이 유사한 댐퍼 7개의 실험결과를 비교하였다. 강판댐퍼로 Ldpd(횡변형 방지 상세) 없는 SI-260, SV-260, SS-260, Ldpd 있는 I-1, V-1, S-1 및 강봉댐퍼인 R20-260을 평가하였다. 또한 단면적이 0.56배인 R15-260도 같이 평가하여, 강봉댐퍼 거동 성능을 적절히 평가하고자 하였다. 중요한 연구결과는 강판댐퍼의 일방향성을 개선한 강봉댐퍼 적용의 우수성이며, 이는 모멘트 저항 능력 및 변위비 평가에서도 확인할 수 있었다. 평가결과, 강봉댐퍼인 R20-260의 성능이 가장 우수한 것으로 평가되었다. 또한 변위비 2.0까지 변형 능력을 나타내어, 충분한 내진성능을 보유한 것으로 판단된다.

방화범죄의 실태와 그 대책 - 관심도와 동기의 다양화에 대한 대응 - (The Reserch on Actual Condition of Crime of Arson Which Occurs in Korea and Its Countermeasures)

  • 최종태
    • 시큐리티연구
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    • 제1호
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    • pp.371-408
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    • 1997
  • This article is the reserch on actual condition of crime of arson which occurs in Korea and its countermeasures. The the presented problem in this article are that (1) we have generally very low rate concern about the crime of arson contrary to realistic problems of rapid increase of crime of arson (2) as such criminal motives became so diverse as to the economic or criminal purpose unlike characteristic and mental deficiency of old days, and to countermeasure these problems effectively it presentation the necessity of systemantic research. Based on analysis of reality of arson, the tendency of this arson in Korea in the ratio of increase is said to be higher than those in violence crime or general fire rate. and further its rate is far more greater than those of the U.S.A. and Japan. Arson is considered to be a method of using fire as crime and in case of presently residence to be the abject, it is a public offense crime which aqccompany fatality in human life. This is the well It now fact to all of us. And further in order to presentation to the crime of arson, strictness of criminal law (criminal law No, 164 and 169, and fire protection law No. 110 and 111) and classification of arsonist as felony are institutionary reinforced to punish with certainty of possibility, Therefore, as tendency of arson has been increased compared to other nations, it is necessary to supplement strategical policy to bring out overall concerns of the seriousness of risk and damage of arson, which have been resulted from the lack of understanding. In characteristics analysis of crime of arson, (1) It is now reveald that, in the past such crime rate appeared far more within the boundary of town or city areas in the past, presently increased rate of arsons in rural areas are far more than in the town or small city areas, thereby showing characteristics of crime of arson extending nation wide. (2) general timetable of arson shows that night more than day time rate, and reveald that is trait behavior in secrecy.(3) arsonists are usually arrested at site or by victim or report of third person(82,9%).Investigation activities or self surrenders rate only 11.2%. The time span of arrest is normally the same day of arson and at times it takes more than one year to arrest. This reveals its necessity to prepare for long period of time for arrest, (4) age rate of arson is in their thirties mostly as compared to homicide, robbery and adultery, and considerable numbers of arsons are in old age of over fifties. It reveals age rate is increased (5) Over half of the arsonists are below the junior high school (6) the rate of convicts by thier records is based on first offenders primarily and secondly more than 4 time convicts. This apparently shows necessity of effective correctional education policy for their social assimilation together with re-investigation of human education at the primary and secondary education system in thier life. The examples of motivation for arosnits, such as personal animosity, fury, monetary swindle, luscious purpose and other aims of destroying of proof, and other social resistance, violence including ways of threatening, beside the motives of individual defects, are diverse and arsonic suicide and specifically suicidal accompany together keenly manifested. When we take this fact with the criminal theory, it really reveals arsons of crime are increasing and its casualities are serious and a point as a way of suicide is the anomie theory of Durkheim and comensurate with the theory of that of Merton, Specifically in the arson of industrial complex, it is revealed that one with revolutionary motive or revolting motive would do the arsonic act. For the policy of prevention of arsons, professional research work in organizational cooperation for preventive activities is conducted in municipal or city wise functions in the name of Parson Taskforces and beside a variety of research institutes in federal government have been operating effectively to countermeasure in many fields of research. Franch and Sweden beside the U.S. set up a overall operation of fire prevention research funtions and have obtained very successful result. Japan also put their research likewise for countermeasure. In this research as a way of preventive fire policy, first, it is necessary to accomodate the legal preventitive activities for fire prevention in judicial side and as an administrative side, (1) precise statistic management of crime of arson (2) establishment of professional research functions or a corporate (3) improvement of system for cooperative structural team for investigation of fires and menpower organization of professional members. Secondly, social mentality in individual prospect, recognition of fires by arson and youth education of such effect, educational program for development and practical promotion. Thirdly, in view of environmental side, the ways of actual performance by programming with the establishment of cooperative advancement in local social function elements with administrative office, habitants, school facilities and newspapers measures (2) establishment of personal protection where weak menpowers are displayed in special fire prevention measures. These measures are presented for prevention of crime of arson. The control of crime and prevention shall be prepared as a means of self defence by the principle of self responsibility Specifically arsonists usually aims at the comparatively weak control of fire prevention is prevalent and it is therefore necessary to prepare individual facilities with their spontaneous management of fire prevention instead of public municipal funtures of local geverment. As Clifford L. Karchmer asserted instead of concerns about who would commit arson, what portion of area would be the target of the arson. It is effective to minister spontaveously the fire prevention measure in his facility with the consideration of characteristics of arson. On the other hand, it is necessary for the concerned personnel of local goverment and groups to distribute to the local society in timely manner for new information about the fire prevention, thus contribute to effective result of fire prevention result. In consideration of these factors, it is inevitable to never let coincide with the phemonemon of arsons in similar or mimic features as recognized that these could prevail just an epedemic as a strong imitational attitude. In processing of policy to encounter these problems, it is necessary to place priority of city policy to enhancement of overall concerns toward the definitive essense of crime of arson.

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Experimental studies and numerical analysis of the shear behavior of fin plates to tubular columns at ambient and elevated temperatures

  • Jones, M.H.;Wang, Y.C.
    • Steel and Composite Structures
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    • 제8권3호
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    • pp.179-200
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    • 2008
  • This paper reports the results of a recent experimental study into the behavior of welded fin-plate connections to both hollow and concrete filled tubular (CFT) columns under shear. Experiments have been performed at both ambient and elevated temperatures with the aid of an electric kiln. The observed failure modes include fracture of the fin plate and tearing out of the tube around the welds. By considering the results of previously published research, the current design method for similar connections under purely tensile load, in CIDECT Guide 9, based on a deformation limit of 3% of the tube width is shown to be inadequate when evaluating the ultimate strength of such connections. By comparing the results from the current test program which failed in the fin-plate with Eurocode guidance for failure of a fin-plate alone under shear and bending load it is shown that the column face influences the overall connection strength regardless of failure mode. Concrete in-fill is observed to significantly increase the strength of connections over empty specimens, and circular column specimens were observed to exhibit greater strength than similarly proportioned square columns. A finite element (F.E.) model, developed using ABAQUS, is presented and validated against the experimental results in order that extensive parametric tests may be subsequently performed. When validating the model against elevated temperature tests it was found that using reduction factors suggested in published research for the specific steel grades improved results over applying the generic Eurocode elevated temperature steel strength reduction factors.

부식된 얇은 원통 압력용기의 파손 거동 해석 (Analysis of Failure Behavior for Thin Cylinder Pressure Vessel with Corrosion)

  • 윤자문;최문오;안석환;남기우;안등 주
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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    • pp.230-232
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    • 2006
  • Failure behaviors of thin cylinder with corrosion are very important for the integrity of boiler and pressure vessel system. In this study, FEM with internal pressure are conducted on 1000 mm diameter (length 3000 mm and thickness, 5.9 mm) SS400 carbon steel. Failure behaviors of locally wall thinned cylinders were calculated by elasto-plastic analysis using finite element method. The elasto-plastic analysis was performed by FE code ANSYS. We simulated various types of local wall thinning that can be occurred at cylinder surface due to corrosion. Locally wall thinned shapes were machined to be different in size along the circumferential or axial direction of straight cylinder. In case of local wall thinned length 30 mm, internal pressure, when the crack initiation and the plastic collapse occur, didn't decrease dramatically even though local wall thinned depth was deep. In 400 mm, the more local wall thinned depth is deep, the more internal pressure decreased dramatically. In degraded materials, crack is easily initiation but plastic collapse was difficult.

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아웃도어 스포츠웨어 구매행동에 관한 질적 연구 -기능성 인지수준과 추구 혜택을 중심으로- (The Qualitative Study on Outdoor Sportswear Purchase Behavior -Focusing on Functional Fabric Awareness Level and Benefits Sought-)

  • 이영주;이은옥
    • 복식문화연구
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    • 제19권5호
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    • pp.1088-1101
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    • 2011
  • The purpose of this study was to examine the outdoor sportswear purchase behavior, outdoorwear sportswear brand preference, functional fabric awareness, and benefits sought. The research was performed through in-depth interview during February to March 2011. Data were collected from 10 consumers who had purchased outdoor sportswear and experienced camping in 6 months. First, the results from study showed that functionality/comfortability, design, color, and brand name were important factors in selecting outdoor sportswear. Offline stores were the main place to purchase, however, internet shopping mall and portal online community were another shopping channel as well. Second, respondents preferred imported outdoor sportswear brand to national brand. According to the study, the respondents trusted the imported outdoor sportswear quality based on the brand name, value, and brand history more than national brand. Third, consumers who had low functional fabric awareness were more likely to evaluate apparel products based on the brand name. Knowledge levels for textile functions were high in elastic, UV protection, air permeable, and antibacterial properties. The essential features for camping were water absorbing and quick dry, water resistance, wind proof, UV protection, and fire retardant properties. Finally the results showed that there were two sportswear benefit soughts: functionality and status ostentation.

긴급상황에 대한 가상현실 선원 훈련 플랫폼 (VR-simulated Sailor Training Platform for Emergency)

  • 박철웅;정진기;양현승
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2015년도 추계학술대회
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    • pp.175-178
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    • 2015
  • 본 논문은 국내외 해양사고 원인의 60-80%에 해당하는 인적과실을 예방하기 위하여 긴급상황에 대한 가상현실 선원 훈련 플랫폼을 제안한다. 제안된 훈련 플랫폼은 가상현실 기술을 통해 긴급 상황 내 절차 숙달을 위한 상호작용 방법과 가상 선박 환경 내에서 군중 에이전트를 제어하는 군중 제어 방법을 제공한다. 제안된 훈련 플랫폼의 상호작용 방법은 훈련 몰입도를 높이기 위하여 음성인식과 행동인식을 사용한다. 군중 제어는 사회적 특성을 반영한 에이전트의 행동모델을 적용하여 자연스러운 시뮬레이션을 제공한다. 제안된 훈련 플랫폼의 효율성을 실험하기 위해 선박 내 화재 상황에 대한 가상 훈련 시나리오를 standalone 훈련 플랫폼으로써 구현하였다.

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Semi-rigid connection modeling for steel frameworks

  • Liu, Yuxin
    • Structural Engineering and Mechanics
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    • 제35권4호
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    • pp.431-457
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    • 2010
  • This article provides a discussion of the mathematic modeling of connections for designing and qualifying structures, systems, and components subject to monotonic or cyclic loading. To characterize the force-deformation behavior of connections under monotonic loading, a review of the Ramberg-Osgood, Richard-Abbott, and Menegotto-Pinto models is conducted, and it is shown that these nonlinear functions can be mathematically derived by scaling up or down a linear force-deformation function. A generalized four-parameter model for simulating connection behavior is investigated to facilitate nonlinear regression analysis. In order to perform seismic analysis of frameworks, a hysteretic model accounting for loading, unloading, and reloading is described using the established monotonic model. For preliminary analysis, a method is provided to quickly determine the model parameters that fit approximately with the observed data. To reach more accurate values of the parameters, the methods of nonlinear regression analysis are investigated and the modified Levenberg-Marquardt and separable nonlinear least-square algorithms are applied in determining the model parameters. Example case studies illustrate the procedure for the computation through the use of experimental/analytical data taken form the literature. Transformation of connection curves from the three-parameter model to the four-parameter model for structural analysis is conducted based on the modeling of connections subject to fire.

The effects of half-section waste tire reinforcement on pipe deformation behavior

  • Erenson, Can;Terzi, Niyazi Ugur
    • Geomechanics and Engineering
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    • 제30권6호
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    • pp.517-524
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    • 2022
  • Every year, millions of waste tires are discarded across the world. Storage of waste tires presents many problems such as fire threats, epidemics, and non-economic factors. Furthermore, the disintegration process of waste tires is not economical or practical due to its time-consuming, and disposal requirements. In this study, half-section waste tires (HSWTs) were integrated with high-density polyethylene (HDPE) pipes under different relative density conditions. The main aim of the study was to reduce the deformation values of embedded HDPE pipes in sandy soil and to evaluate the soil-pipe interaction. In comprehensive laboratory tests, half-section waste tires were integrated in two different ways: in the middle of the pipeline and along the pipeline. Accordingly, it was concluded that the effectiveness of waste tires reduces the deformation and bending moment values in the critical regions of pipes. As a result of reinforcement in the mid-point of the pipe defined as the most critical region, 52% and 36% less deformation was observed in the crown and springlines of the pipe, respectively. In addition, the bending moment values for the same critical section were determined to be 40% less in the crown and 28% less in the springline regions of the pipe.

Finite element analysis and theoretical modeling of GFRP-reinforced concrete compressive components having waste tire rubber aggregates

  • Mohamed Hechmi El Ouni;Ali Raza
    • Steel and Composite Structures
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    • 제52권1호
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    • pp.57-76
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    • 2024
  • The management of waste tire rubber has become a pressing environmental and health issue, requiring sustainable solutions to mitigate fire hazards and conserve natural resources. The performance of waste materials in structural components needs to be investigated to fabricate sustainable structures. This study aims to investigate the behavior of glass fiber reinforced polymer (GFRP) reinforced rubberized concrete (GRRC) compressive components under compressive loads. Nine GRRC circular compressive components, varying in longitudinal and transverse reinforcement ratios, were constructed. A 3D nonlinear finite element model (FEM) was proposed by means of the ABAQUS software to simulate the behavior of the GRRC compressive components. A comprehensive parametric analysis was conducted to assess the impact of different parameters on the performance of GRRC compressive components. The experimental findings demonstrated that reducing the spacing of GFRP stirrups enhanced the ductility of GRRC compressive components, while the addition of rubberized concrete further improved their ductility. Failure in GRRC compressive components occurred in a compressive columnar manner, characterized by vertical cracks and increased deformability. The finite element simulations closely matched the experimental results. The proposed empirical model, based on 600 test samples and considering the lateral confinement effect of FRP stirrups, demonstrated higher accuracy (R2 = 0.835, MSE = 171.296, MAE = 203.549, RMSE = 195.438) than previous models.

방화범죄의 경비예방 전략에 관한 비교연구 - 연쇄방화범과 단순방화범의 행위적 특성을 중심으로 - (A Comparative Study of the Security Prevention Strategies on Arson: Focused on the Behavioral Characteristics between Serial Arsonists and Simple Arsonists)

  • 유완석;황성현
    • 시큐리티연구
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    • 제29호
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    • pp.139-162
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    • 2011
  • 본 연구의 목적은 연쇄방화범과 단순방화범의 사회경제적 특징, 범죄현장에서의 행위적 특징 등에서 어떤 차이점이 발견되는지를 살펴보고 이를 토대로 공경비와 민간경비 차원에서의 방화예방책을 논의하는 데 있다. 연구에 사용된 데이터는 경찰청에서 운영 중인 과학적 범죄분석시스템(SCAS) 자료를 기본으로 하였으며, 수사종합검색시스템(CRIFISS), 범죄정보관리시스템(CIMS) 자료를 보충적으로 활용하였다. 구체적으로 2000년 초부터 국립과학 수사연구소 범죄분석실과 경찰청 범죄행동분석팀에서 합동으로 실시한 전국의 주요 방화사건 중 기소 전 경찰 수사단계에서의 피의자에 대한 면접자료 160건을 연구분석 자료로 사용하였다. 연쇄방화범과 단순방화범의 행위적 특성에 대한 교차분석결과 다른 독립변인들에 비해 가장 뚜렷한 차이점이 발견되었다. 즉 연쇄방화범은 피해장소나 피해대상을 노상이나 무작위 장소의 쓰레기나 적치물을 이용하여 방화하는 경향이 높으며, 그런 장소에서 쉽게 구할 수 있는 종이류를 사용하며, 사전에 방화도구를 준비하지 않고, 현장에서 바로 입수 할 수 있는 것들을 사용하는 경향이 있었다. 또한 범죄 후 사법기관에 검거될 수 있다는 두려움이 단순방화범에 비해 훨씬 약하기 때문에 방화 후 현장을 조작하지 않을 가능성 높고, 도보로 현장을 빠져 나오는 경향이 높았다. 또한 방화의 원인이 흥분이나 현실불만일 가능성이 높기 때문에 방화 피해자와 비면식일 가능성이 높고, 흥분이나 현실불만을 고취시키기 위해 음주상태에서 방화사건을 저지를 가능성이 높은 것으로 나타났다. 이 연구는 방화범에 대한 문헌연구가 아닌 경찰청이 보유한 실증적, 경험적 자료를 사용했기 때문에 향후 방화범죄에 대한 연구와 공경비와 민간경비 강화의 모델 구축에 중요한 토대가 될 수 있는 의미 있는 연구결과를 발견했다는 점에서 연구의 중요성이 부각될 수 있을 것이다.

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