• Title/Summary/Keyword: Impact Safety

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Development of Non-Redirective Crash Cushion for Bridge Piers Considering Occupant Safety (탑승자 안전도를 고려한 교각 방호시설물 개발에 관한 연구)

  • Park, Jaehong;Sung, Jung Gon;Nam, Min Gyun;Yun, Duk Geun
    • Journal of the Korean Society of Safety
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    • v.33 no.5
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    • pp.120-126
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    • 2018
  • The traffic accident types are largely classified into vehicle to vehicle accident, vehicle-to-person accident and single-vehicle. Especially, the single-vehicle accident types are severe when the vehicle crashed into road facilities such as bridge, piers, utility poles. The severity of single-vehicle accidents are ten times higher than that of all other accidents types. It is needed to consider to reduce accident severity. This study was conducted to develop crash worthy safety design facility to ensure the vehicle occupant safety. The simulation and the crash tests were conducted for assessment of the safety performance to check the criteria of CC2(Crash Cushion 2) level. THIV(Theoretical Head Impact Velocity) and PHD(Post-impact Head Deceleration) were used to assess occupant impact severity for crashes. The non-redirection collision test conditions for 900 kg and 1,300 kg-head on crash tests, 900 kg-1/4 offset crash tests, 1,300 kg-head on crash test with $15^{\circ}$angle were conducted. The simulation and experiment test result showed that THIV values were below 44 km/h criterion, PHD values were below the 20G. The development non-redirective crash cushion is expected to be used for the fixed object such as bridge piers for assuring occupant safety.

Work Condition Effects of Construction Field Managers and Safety Managers on Job Satisfaction (건설현장 관리자와 안전관리 담당자의 근로조건이 직무만족에 미치는 영향 분석)

  • Choi, Jae-Kyu;Hong, Jung-Su
    • Journal of the Korea Institute of Building Construction
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    • v.17 no.1
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    • pp.91-100
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    • 2017
  • The safety management is one of important factors. However, the satisfaction of safety manager is lowering. Therefore, this study focuses on comparing the impact that working conditions have on the job satisfaction of field and safety manager in construction field. The results of in this study, the basic wage, medical care, and leisure activity were analyzed as a positive impact on job satisfaction. In addition, the comparison result of the field manager and safety manager showed that safety manager appeared to be a greater impact on the basic wage than the field manager. Also, this study showed that the medical care and leisure activity have a positive impact on the job satisfaction of field manager, but the industrial accident and accommodation facility have a positive impact on the job satisfaction of safety manager.

Numerical study on tensioned membrane structures under impact load

  • Zhang, Yingying;Zhao, Yushuai;Zhang, Mingyue;Zhou, Yi;Zhang, Qilin
    • Structural Engineering and Mechanics
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    • v.71 no.2
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    • pp.109-118
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    • 2019
  • This paper presents the numerical simulation of membrane structure under impact load. Firstly, the numerical simulation model is validated by comparing with the test in Hao's research. Then, the effects of the shape of the projectile, the membrane prestress and the initial impact speed, are investigated for studying the dynamic response and failure mechanism, based on the membrane displacement, projectile acceleration and kinetic energy. Finally, the results show that the initial speed and the punch shape are related with the loss of kinetic energy of projectiles. Meanwhile, the membrane prestress is an important factor that affects the energy dissipation capacity and the impact resistance of membrane structures.

The Relationship between the Load Carrying Capacity and Transformed Impact Factor of Highway Bridge (교량의 공용내하력과 환산충격계수 관계 연구)

  • Chai, Won-Kyu;Lee, Myeong-Gu
    • Journal of the Korean Society of Safety
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    • v.27 no.6
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    • pp.138-143
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    • 2012
  • In this thesis, the relationship between the load carrying capacity and the transformed impact factor of the highway bridges were studied. The bridges are classified according to superstructures type. The result of the comparison between the load carrying capacity and the transformed impact factor, if the load capacity ratio of 0.57, the transformed impact factor was less in order of RC T-beam bridge, RC slab bridge, PC beam bridge, I-beam bridge. By the regression analysis on these results, the empirical formulae to predict the the load carrying capacity of bridge were suggested.

A Consideration on the Results of Side Impact and Pole Side Impact Tests in 2011 KNCAP (2011 KNCAP 측면충돌 및 기둥측면충돌 시험결과 고찰)

  • Lee, Dongjun;Choi, Youngtae;Lee, Kwangwon;Lim, Jaemoon
    • Journal of Auto-vehicle Safety Association
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    • v.3 no.2
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    • pp.22-27
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    • 2011
  • The side impact test in the Korean New Car Assessment program (KNCAP) has been conducted since 2003. The side impact test method has been contributed to the improvement of the vehicle side structure and the enhancement of the occupant protection performance for the domestic vehicles. The pole side impact test method introduced in the KNCAP in 2010 to enhance the head protection under the severe side crash environment. The pole side impact test is optional for the additional score to be added to the overall rating score. The test results of side and pole side impact test for five vehicles were introduced and compared.

The Effects of Temperature Change on the Bending Strength of CF/PEEK Laminates after Impact (온도변화가 CF/PEEK 적층재의 충격 후 굽힘강도에 미치는 영향)

  • 양인영;정종안;나승우
    • Journal of the Korean Society of Safety
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    • v.18 no.2
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    • pp.34-39
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    • 2003
  • In this paper, when CF/PEEK laminates for high efficiency space structure are subjected to FOD(Foreign Object Damage), the effects of temperature change on the impact damages(interlaminar separation and transverse crack) of CF/PEEK laminates and the relationship between residual lift and impact damages are experimentally investigated. Composite laminates used in this experiment are CF/PEEK orthotropic laminated plates, which have two-interlaces [$0^{\circ}_4/90^{\circ}_8/0^{\circ}_4$]. A steel ball launched by the air gun collides against CF/PEEK laminates to generate impact damages. And then CF/PEEK specimens with impact damages are observed by a scanning acoustic microscope under room and high temperatures. In this experimental results, various relations are experimentally observed including the delamination area vs. temperature change, the bending strength vs. impact energy and the residual bending strength vs. impact damage of CF/PEEK laminates.

Behavioral Characteristics Investigation of Rack Structure Depending on Forklift Impact Scenarios and Storage Distributions (지게차 충돌 위치 및 보관물류 분포에 따른 선반구조물의 거동특성분석)

  • Ok, Seung-Yong;Kwon, Oh-Yong;Paik, Shin Won
    • Journal of the Korean Society of Safety
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    • v.28 no.6
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    • pp.49-56
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    • 2013
  • The statistics of recent accidents in warehouses show that a heavy toll of lives were produced by various accidents, e.g. collision, overturn, fall, slip, exposure to harmful substances or environments, etc. Of significant concern amongst them is the collision, especially the collision between forklift and storage rack structure. Accordingly, this study focuses on behavioral characteristics of rack structure subjected to dynamic impact loading of a forklift. For this purpose, time-domain response analysis has been performed on a standard 2-bay six-story rack structure consisting of columns, beams and bracing members with perforated open section. In order to investigate the most critical scenario, the impact loads are applied in both down-aisle and cross-aisle directions, and the impact locations are also varied along the shelves of the palettes. In order to deal with storage distributions, three types of rack structures are further taken into account: original empty rack structure with no storage, half-loaded rack structure and fully-loaded rack structure. The numerical simulation results demonstrate that the dynamic characteristics of the rack structure are significantly dependent on the distribution of the storage goods and its natural period varies from 0.24sec to 1.06sec, approximately 4.4 times. Further, the parametric studies show that the forklift impact is most critical to the safety of the rack structure when it collides either at the base or at the top of the rack structure.

A Study on the Reasonable Estimation of Consequence of Chemical Release (화학사고 피해영향 범위의 합리적 산정방안에 대한 연구)

  • Cho, Guysun;Lim, Juntaig;Han, Jeongwoo;Baek, Eunsung;Yu, Wonjong;Park, Kyoshik
    • Journal of the Korean Institute of Gas
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    • v.24 no.5
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    • pp.20-28
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    • 2020
  • In this study, the damage impact range in the case of a hydrofluoric acid leak accident was predicted using formula calculation, impact assessment simulations, and CFD simulations, and the results were compared and analyzed with the actual environmental impact report. Formula calculation was performed by using the leak source model and diffusion model. Impact assessment simulation was performed by KORA provided by the Korean Ministry of Environment, ALOHA by the United States Ministry of Environment, and PHAST, which is relatively widely used among commercialization programs, and the STAD-CMM+program for CFD simulation. Was utilized. Considering convenience, speed, acceptability, and economics from the user's perspective, ALOHA and KORA were the most appropriate methods for predicting the impact of hydrofluoric acid leakage. In addition, the results of this study will help to reduce unnecessary regulations in the process of government policy development and optimize the investment in the safety field of the company, effectively utilizing the limited resources of the government and the company.

A Study on the Prediction Technique of Impact Dispersion Area for Flight Safety Analysis (비행안전분석을 위한 낙하분산영역 예측 기법에 대한 연구)

  • Choi, Kyu-Sung;Sim, Hyung-Seok;Ko, Jeong-Hwan;Chung, Eui-Seung
    • Aerospace Engineering and Technology
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    • v.13 no.2
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    • pp.177-184
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    • 2014
  • Flight safety analyses concerned with Launch Vehicle are performed to measure the risk to the people, ship and aircraft using impact point and impact dispersion area of debris generated by on-trajectory failures and malfunction turns. Predictions of impact point and impact dispersion area are essential for launch vehicle's flight safety analysis. Usually, impact dispersion area can be estimated in using Monte-Carlo simulation. However, Monte-Carlo method requires more several hundreds of iterative calculations which requires quite some time to produce impact dispersion area. Herein, we check the possibility of applying JU(Julier Uhlmann) transformation and Taguchi method instead of Monte-Carlo method and we propose a best method in terms of compuational time to produce impact dispersion area by comparing the results of the three methods.

The Impact of Ethical Leadership on Safety Behavior: Focusing on the Sequential Mediating Effects of Organizational Trust and Organizational Commitment, and the Moderating Effects of Authentic Leadership (윤리적 리더십이 안전 행동에 미치는 영향: 조직 신뢰와 조직 몰입의 순차적 매개 효과, 그리고 진정성 리더십의 조절 효과를 중심으로)

  • Yunsook Hong
    • Journal of the Korea Safety Management & Science
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    • v.25 no.2
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    • pp.175-185
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    • 2023
  • Prior studies focusing on safety behavior have not given sufficient consideration to the potential impact exerted by different leadership styles. Of these various styles, my attention is specifically drawn to the influence of ethical leadership on safety behavior. In this paper, I delve into the influence of ethical leadership on safety behavior, shedding light on both the underlying mechanisms(mediators) and a significant contextual factor(moderator). I probe into the successive mediating roles of employees' trust in the organization and their commitment to it, within the context of the relationship between ethical leadership and safety behavior. Further, I posit that authentic leadership positively adjusts the connection between ethical leadership and organizational trust. My findings underscore that ethical leadership enhances employee safety behavior, facilitated by the chain mediation of trust in the organization and organizational commitment. Moreover, I discover that authentic leadership, as a positive moderator, magnifies the favorable impact of ethical leadership on organizational trust. This paper will also articulate the theoretical implications, practical applications, and limitations of the study.