• 한국안전학회지
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• 제23권1호
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• pp.1-11
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• 2008

In this study, small punch test and tensile test were performed with specimens directly machined from an ASTM A53 grade B carbon steel pipe at which an explosion accident was occurred in the Heavy Oil Unit. Main damage mechanism of the pipe was known as a high temperature hydrogen attack(HTHA). Effects of HTHA on the mechanical strength change of the A53B steel were studied in detail. Small punch test results have showed that maximum reaction forces, SP energy and ductility were decreased at hydrogen attacked part of the pipe compared with sound part of the pipe. Yield strength and tensile ultimate strength were calculated with the obtained small punch test curve results using different methods and compared the estimation methods. Small punch test simulation has been also performed with the finite element method and then mechanical strength, equivalent strain and fracture toughness were calculated with the obtained numerical analysis results. It was shown that the fracture toughness data calculated from small punch equivalent energy obtained by the finite element analysis for SP test was very low at the hydrogen attacked part.

• 디지털융복합연구
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• 제19권7호
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• pp.155-162
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• 2021

본 연구의 목적은 안전보건과 관련하여 경영진의 지지가 근로자 안전인식에 미치는 영향을 정량적으로 분석하는 것이다. 1990년대 이후로 우리나라는 국가경쟁력이 급속하게 상승하고 있지만, 아직까지 산업재해 예방과 대처를 위한 노력이 미흡한 실정이며, 특히 2020년대에 들어서면서 기업의 중대재해 책임을 강화하려는 움직임이 크게 일어나고 있다. 본 연구에서는 경영진의 지지가 해당 업체의 안전보건 관련 조직 및 제도, 의사소통에 어떻게 영향을 미치고, 궁극적으로 근로자들이 안전의식에 어떠한 영향을 미치는 지를 구조방정식모델을 구성하여 정량적으로 분석한다. 구조방정식모델을 위해 산업안전보건연구원에서 수행한 4,169명의 설문지가 관측변수로 활용되었으며, 5개의 가설이 설정되어 가설검증이 이루어졌다. 안전보건 경영과 관련된 경영진의 지지가 높아지면 조직 내의 안전보건 관련 조직과 제도의 구성 및 운영, 안전보건 관련 의사소통이 활발해지고, 최종적으로 사업장에서의 근로자 안전의식 및 행동도 증대되는 효과가 있는 것으로 분석되었다. 본 연구결과는 안전보건과 관련된 조직, 제도, 의사소통 등의 제반 조치 이전에 경영진의 안전보건에 대한 중요성 인식 증대가 필요함을 함의한다.

• 한국염색가공학회지
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• 제26권3호
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• pp.173-180
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• 2014

Fall-arrest system have been widely applied to provide a safe stop during fall incidents for occupational activities. This research object to evaluate the energy capacity of fall arrest shock energy absorber lanyard in relation to the used super fiber. In this work, shock energy absorber lanyard was prepared using high tenacity PET, high tenacity PET/P-aramid and high tenacity PET/UHMWPE, respectively. Dynamic load and static load tests based on the Korea fall protection equipment standard(Korea Occupational Safety & Health Agency standard 2013-13) were conducted. Maximum arrest force by dynamic load test of shock energy absorber showed below 6,000N. Also, static strength by static load test of lanyard and rope remains 15,000N and 22,000N for 1 min.

• 대한인간공학회지
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• 제28권4호
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• pp.139-145
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• 2009

This study concerned with the characteristics and causes of musculoskeletal disorders (MSDs) for employees aged 50 years or older. In order to do this, based on 8,011 accident analysis reports, we analyzed the differences of characteristics between groups under 50 years and 50 years or more in terms of gender, occupation, duration of employment, part of body, industry, size of business and work-related factors. Results show that the distributions of the injuries aged 50 years or older are statistically different from those of the injuries under 50 years. Also, older employees have high relationship between repetition, or contact stress/vibration and upper extremity MSDs. These findings can be used to develop more effective MSD prevention programs for older employees.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 Asia Navigation Conference
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• pp.102-112
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• 2004

In this paper, we propose a human model for analysis for human work pattern or human fault, where a gantry crane simulator is used to survey the property of human operation. From the input and output of gantry crane response, we make a human operation model by using conventional ARX identification method. For identify the human model, we assume the eight inputs and two outputs. By using the input/output data, we estimate the parameters of ARX of the human system model. For verify the proposed method, we compared the real data with the modeled data, where three kinds of work trajectory path are used.

• 한국항해항만학회지
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• 제29권2호
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• pp.135-140
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• 2005

In this paper, we propose a human model for analysing the human work pattern or human fault, where a gantry crane simulator is used to survey the property cf human operation From the input and output cf gantry crane response, we make a human operation model by using conventional ARX identification method To identify the human model, we assume the eight inputs and two outputs. By using the achieved input/output data, we estimate the parameters of ARX for the human work model. To verify the proposed method, we compared the real data with the modeled data, where three kinds of work trajectory path are used.

• 한국안전학회지
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• 제26권3호
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• pp.59-62
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• 2011

Among the accidents and failures that occur during concrete construction, many are formwork failures which usually happen when concrete is being placed. A system of formwork filled with wet concrete has its weight at the top and is not basically a stable structure. Slab formwork consists of sheathing, stringer, hanger and shore. There are several types of adjustable shores. In construction site, pipe supports are usually used as a shore of slab formwork. In this study, pipe support systems with/without horizontal connector were measured by buckling test. Buckling load of respective pipe support system was analyzed by structural analysis program(MIDAS). Buckling load of pipe support with/without horizontal connector was got by test and structural analysis. According to these results, we know that horizontal connector made pipe support system very safe. Buckling load of pipe support with horizontal connector is 56% higher than that without horizontal connector. So horizontal connector is important in slab formwork systems. Finally, the present study results will be used to design slab formwork system safely in the construction sites.

• 한국건축시공학회지
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• 제7권3호
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• pp.115-122
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• 2007

As buildings become higher, larger, and more complex, safety issues for construction workers working at such environments become more important. We analyzed 83 critical accident cases reported to the KOSHA(Korea Occupational Safety & Health Agency) for construction cranes by types of cranes and by patterns of accidents and causes. There are more number of accidents related to mobile cranes than that related to tower cranes, but the numbers of dead were similar in both cases. The most dominant cause of crane accidents was "fall of materials". We also analyzed the cases of crane accidents using the FMEA(Failure Mode and Effect Analysis) in order to set up a priority for safety management and also to prioritize research and development items relating tower cranes. In the process, we tried to eliminate subjective indexes such as an expert group survey and use objective and quantitative indexes. As a result, it was found that critical crane accidents occurs most during the "lifting and translating" activity.

• 한국안전학회지
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• 제35권5호
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• pp.1-8
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• 2020

Mobile elevating work platforms (MEWPs) consist of a work platform, extending structure, and chassis, and are used to move persons to working positions. MEWPs are useful but are composed of pieces of equipment, and accidents do occur owing to equipment defects. Among these defects, accidents caused by the fracture of bolts fixed to the extension structure and swing system are increasing. This paper presents a failure analysis of the fixing bolts of MEWP. Standard procedure for failure analysis was employed in this investigation. Visual inspection, chemical analysis, tensile strength measurement, microstructural characterization, fractography analysis by Optical Microscope(OM) and Scanning Electron Microscopy(SEM), and finite element analysis (FEA) were used to analyze the failure of the fixing bolts. Using this failure analysis approach, we found the root cause of failure and proposed a means for solving this type of failure in the future. First, the chemical composition of the fixing bolt is obtained by a spectroscopy chemical analysis method, which determined that the chemical composition matched the required standard. The tensile test showed that the tensile and yield strengths were within the required capacity. The stress analysis was carried out at five different boom angles, and it was determined that the fixing bolt of MEWP can withstand the loads at all the boom angles. The outcomes of the fatigue analysis revealed that the fixing bolt fails before reaching the design requirements. The results of the fatigue analysis showed primarily that the failure of the fixing bolt was due to fatigue. A visual inspection of the fractured section of the fixing bolt also confirmed the fatigue failure. We propose a method to prevent failure of the fixing bolt of the MEWP from four different standpoints: the manufacturer, safety certification authority, safety inspection agency, and owner.

• 한국건축시공학회지
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• 제19권3호
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• pp.273-279
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• 2019

본 연구에서는 건설현장에 설치된 표지판을 측색하여 색기준에 대한 적합성 검토와 현장여건에 적합한 관리 방안을 제시하고자 하였으며, 현장에 설치된 안전표지판은 관련기준에 적합한 정도가 적색 33%, 황색 22%, 청색 3%, 녹색 28%로 나타나 각각의 현장에 설치된 법적인 기준에 대부분 적합하지 않은 것으로 나타났으며, 청색 안전표지판에 대하여 보다 적극적인 제조생산과 관리에 대한 관련기관의 감독이 필요하다.