Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Society of Safety
Journal Basic Information
Journal DOI :
The Korean Society Safety
Editor in Chief :
Volume & Issues
Volume 21, Issue 6 - Dec 2006
Volume 21, Issue 5 - Oct 2006
Volume 21, Issue 4 - Aug 2006
Volume 21, Issue 3 - Jun 2006
Volume 21, Issue 2 - Apr 2006
Volume 21, Issue 1 - Feb 2006
Selecting the target year
Characteristics of High Temperature Fatigue Fracture in Spring Steels after Shot Peening
Park, Keyung-Dong ; Shin, Yeong-Jin ;
Journal of the Korean Society of Safety , volume 21, issue 4, 2006, Pages 1~6
The lightness of components that was required in automobile and machinery industry requires high strength of components. In particular, manufacturing process and new materials development for solving the fatigue facture problem attendant upon high strength of suspension of automobile are actively advanced. In this paper, the effect of compressive residual stress of spring steel(JISG SUP-9)by shot-peening on fatigue crack growth characteristics in high temperature(
)was investigated with considering fracture mechanics. So, we can obtaint the followings. (1) Compressive residual stress is decreased with increasing the test temperature. (2) The effect of compressive residual stress on fatigue crack growth behavior in high temperature is increased below
. (3) It was investigated by SEM that the constraint of compress residual stress for plastic zone of fatigue crack tip was decreased in high temperature as compared with room temperature.
A Study of Smoke Exhaust Rate for the Transverse Ventilation with Oversized Exhaust Ports in Road Tunnel
Yoo, Ji-Oh ; Yoon, Sung-Wook ; Rie, Dong-Ho ;
Journal of the Korean Society of Safety , volume 21, issue 4, 2006, Pages 7~12
Recently, the application of transverse ventilation system with oversized exhaust ports has been increased in bidirectional road tunnel in order to improve smoke exhaust ability. Therefore, in this study, for decision of the optimal smoke exhaust rates in the transverse ventilation system, several standards of nations are compared and numerical simulations with variations of exhaust flow rates are carried out in terms of smoke spread distance by FDS ver. 3.1. As results, in the case of no internal longitudinal air velocity in tunnel, the smoke exhaust rate of
(the smoke generation rate at HRR of 20MW) is sufficient enough to limit the smoke spread within 250m in 6 minutes after the fire. However, in the case of the internal longitudinal air velocity at 2.5m/s, the smoke exhaust rate should be increased
Material Degradation in KS D 3503 SS400 Rolled Steel at
Baek, Un-Bong ; Park, Jong-Seo ; Nahm, Seung-Hoon ;
Journal of the Korean Society of Safety , volume 21, issue 4, 2006, Pages 13~18
In spite of frequent defect in industrial boilers, life assessment or diagnostic method for them has not been actively studied. In this research, SS400 carbon steel used in industrial boilers is simulated with artificial aging heat treatment. To do qualitative life assessment, differences in micro-structures and hardness of SS400 by the degradation time are studied. In addition, variation in material properties by aging was observed with the tensile test at room temperature and
and changes in ductile to brittle transition temperature was observed with the charpy impact test performed at several test temperature.
Fatigue Crack Growth Behavior of Gray Cast Iron for Brake Disc of a Passenger Car
Kim, Ho-Kyung ; Park, Jin-Ho ; Yang, Kyoung-Tak ; Choi, Deok-Ho ;
Journal of the Korean Society of Safety , volume 21, issue 4, 2006, Pages 19~24
Fatigue crack propagation tests for the brake disc cast iron were conducted for investigating fatigue crack propagation rate(da/dN), crack propagation path and fracture toughness(
) of the material. The threshold stress intensity factor range,
, was found to be about
at the stress ratio of R = 0.1. Also, fracture toughness value was determined to be
. Irregular fatigue fracture surfaces were observed, indicating that fatigue crack growth occurred at the interface between randomly scattered flak graphite and ferrite, where the interfacial strength was relatively weak.
Distributed Control of DC Servo Motor on LonWorks-IP Virtual Device Network for Predictive and Preventive Maintenance
Song, Ki-Won ;
Journal of the Korean Society of Safety , volume 21, issue 4, 2006, Pages 25~32
LonWorks over IP(LonWorks-IP) virtual device network(VDN) is an integrated form of LonWorks device network and IP data network. In especially real-time distributed servo applications on the factory floor, timely response is essential for predictive and preventive maintenance. The time delay in servo control on LonWorks-IP based VDN has highly stochastic nature. LonWorks-IP based VDN induced transmission delay deteriorates the performance and stability of the real-time distributed control system and can't give an effective preventive and predictive maintenance. In order to guarantee the stability and performance of the system, and give an effective preventive and predictive maintenance, LonWorks-IP based VDN induced time-varying uncertain time delay needs to be predicted and compensated. In this paper new Pill control scheme based on Smith predictor, disturbance observer and band pass filter is proposed and tested through computer simulation about position control of DC servo motor. It is shown that how can the proposed control scheme be designed to minimize the effects of uncertain varying time delay and model uncertainties. The validity of the proposed control scheme is compared and demonstrated with the comparison of internal model controllers(IMC) based on Smith predictor with and without disturbance observer.
Assessment of Material Risk and Residual Life of CrMoV Turbine Rotor Considering High Temperature Material Degradation
Ma, Young-Wha ; Lee, Jin-Sang ; Yoon, Kee-Bong ;
Journal of the Korean Society of Safety , volume 21, issue 4, 2006, Pages 33~41
Material degradation should be considered to assess integrity and residual life of high temperature equipments. However, the property data reflecting degradation are not sufficient for practical use. In this study measuring properties for 1Cr-1Mo-0.25V forging steel generally used for turbine rotor was carried out. Degradation was simulated by isothermal ageing. heat treatment and variation of microstructure was observed. Mechanical properties such as tensile strength, impact energy, hardness and fracture toughness were measured. Assuming a semi-elliptical surface crack at the bore hole in a turbine rotor, material risk was estimated by using the aged material property data obtained in this study. Safety margin was decreased and life of the rotor was exhausted. This procedure can be used in assessing the residual life of a turbine rotor due to material degradation.
Estimation of the Number of Physical Flaws Using Effective POD
Lee, Jae-Bong ; Park, Jae-Hak ; Kim, Hong-Deok ; Chung, Han-Sub ;
Journal of the Korean Society of Safety , volume 21, issue 4, 2006, Pages 42~48
The strategies of maintenance and operation are usually established based on the number of flaws and their size distribution obtained from nondestructive inspection in order to preserve safety of the plant. But non destructive inspection results are different from the physical flaws which really exist in the equipments. In case of a single inspection, it is easy to estimate the number of physical flaws using the POD curve. However, we may be faced with some difficulties in obtaining the number of physical flaws from the periodic in-service non destructive inspection data. In this study a simple method for estimating the number of physical flaws from periodic in-service nondestructive inspection data was proposed. In order to obtain the flaw growth history, the flaw growth was simulated using the Monte Carlo method and the flaw size and the corresponding POD value were obtained for each flaw at each periodic inspection time. The flaw growth rate used in the simulation was statistically calculated from the in-service inspection data. By repeating the simulation numerous flaw growth data could be generated and the effective POD curve was obtained as a function of flaw size. From the effective POD curve the number of physical flaws was obtained. The usefulness and convenience of the proposed method was evaluated from several applications and satisfactory results were obtained.
Fracture Resistance Characteristics of SA516-Gr.70 Steel Plate for RCS Piping Elbow and Support Skirt
Son, Jong-Dong ; Lim, Man-Bae ;
Journal of the Korean Society of Safety , volume 21, issue 4, 2006, Pages 49~54
The evaluation of elastic-plastic fracture characteristic was investigated in ferrite steel SA 516- Gr70 used for reactor coolant piping elbow and support skirt of pressure vessels. This paper describes the effect of temperature on J-R curve characteristic of this material. The elastic-plastic fracture mechanics parameter J is obtained with unloading compliance method. The test method were analyzed according to ASTM E 813-89 and E 1152-89. Unloading compliance
tests were performed on 1 CT specimens at varied temperatures from
using a high temperature extensometer. At all temperature, valid
measurements could be made and
decreased with increasing temperature. SEM fractography schematically illustrates microvoid initiation, growth and coalescence at the tip of a preexisting crack.
Electrical and Mechanical Properties of Gamma-ray Irradiated LDPE/EVA Blends
Lee, Chung ; Kim, Ki-Yup ; Kim, Gyu-Baek ; Jung, Sang-Ho ; Ryu, Boo-Hyung ;
Journal of the Korean Society of Safety , volume 21, issue 4, 2006, Pages 55~59
The radiation effects on electrical and mechanical properties of LDPE/EVA blends with various vinyl acetate contents were investigated. Radiation degradation of LDPE/EVA blends were studied by using gelation, volume resistivity, permittivity, dissipation factor, elongation at break, and E-modulus. As vinyl acetate contents increased in LDPE/EVA blends, electrical insulation characteristics were deteriorated, but flexibility was improved. As irradiation doses increased, electrical insulation characteristics were improved, but flexibility was deteriorated.
A Study for Development and Characteristics of Electrostatic Eliminator Suitable for the Super Clean Room Less than Class 100(I)
Jung, Yong-Chul ; Park, Hoon-Kyu ; Lee, Dong-Hoon ;
Journal of the Korean Society of Safety , volume 21, issue 4, 2006, Pages 60~65
It is a well known fact that LCD is a central part of the IT industry which is important in the present and the future. But the biggest problem of LCD manufacturing is maintaining a cleaning room environment and administration. Therefore the purpose of this study is to first, prevent the yield depreciation and damage of products, and second, protect the worker ftom accidental electrostatic discharge during LCD manufacture. The soft x-ray ionizer is a type of electrostatic reducer device. It protects against electrostatic discharge in the cleaning room environment and is a necessary environmental factor during LCD production. The positive aspects of the soft x-ray are its shorter time and wider angle of exposure. But the negative aspect of the soft x-ray is its need for several shielding of protection from the harmful x-ray exposure. On this study, the development of the Air Nozzle-type ionizer to amend and refine some problems. For example, examined the electrostatic reduce device of a soft x-ray type and discovered the ion did not go inside well. also workers to be free from danger. An Air Nozzle-type ionizer is comprised of soft x-ray radiation and ionized air production. Air is injected through the nozzle after being ionized from radiation. It supplies air keeping the same pressure into the end foundation of ion production. The soft x-ray is the structure which radiates ionized air through the nozzle (21 holes) having micro holes of the ionizable radiation after ionizing the inside air by the ion production. A worker does not need a cover to protect against x-rays and the Air Nozzle-type ionizer is easy to set up and is more effective at eliminating electrostatic.
Measurement of Autoignition Temperature of o-Xylene+n-pentanol System
Ha, Dong-Myeong ; Lee, Sung-Jin ;
Journal of the Korean Society of Safety , volume 21, issue 4, 2006, Pages 66~72
An accurate knowledge of the AITs(autoignition temperatures) is important in developing appropriate prevention and control measures in industrial fire protection. The measurement of AITs are dependent upon many factors, namely initial temperature, pressure, vessel size, fuel/air stoichiometry, catalyst, concentration of vapor, ignition delay time. The values of the AITs used process safety are normally the lowest reported, to provide the greatest margin of sefety. This study measured the AITs of o-xylene+n-pentanol system from ignition delay time by using ASTM E659-78 apparatus. The experimental AITs of o-xylene and n-pentanol were
, respectively. The experiment AITs of o-xylene+n-pentanol system were a good agreement with the calculated AITs by the proposed equations with a few A.A.D.(average absolute deviation).
Appropriate Rate for Estimating Safety Management Cost in Civil Work
Son, Ki-Sang ; Lee, Gi-Tae ; Park, Jong-Keun ; Park, Jung-Bong ;
Journal of the Korean Society of Safety , volume 21, issue 4, 2006, Pages 73~84
Standard safety management cost system was established in 1988 as a decree Number of 88-13, first time. And then, it has been revised fourteen times, up to now. A lot of practical investigations have been made for the revision but many problems at sites are continued to be put out so that it should be revised. This study is to find out hazard level of each work kinds through questionnaire and interview and investigate analyze the status which standard safety management costs have been used. Also, this study is to show reasonable rates of standard safety management costs in construction industry and to set up countermeasures against those problem after reviewing its status in korea with in Japan and Europe. Budget and actually performed amount of safety management costs in this study are investigated. costs for temporary work which is clarified in Japan is collected in order to compare domestic cost rate with Japanese one related to the total project amount. This study is to investigate eleven project kinds of domestic system, first, and to investigate eleven items of apartment bldg, office, civil work such as bridge, tunnel, dam, plant etc, secondly. Additionally, three items of gymnasium, railway, particular steel tower are investigated in this study. Also this study is to investigate and analyze performed costs of presently processing worker finished work so that it shows a new reasonable rate against standard safety management costs in construction industry, in order to make basical data and material to be systemized.
Evaluation of Effect for Connector System in Reinforced Earth Retaining Wall
Lee, Jun-Dae ; Heo, Yol ; Ahn, Kwang-Kuk ; Lee, Yong-Jun ;
Journal of the Korean Society of Safety , volume 21, issue 4, 2006, Pages 85~94
In this study, in order to evaluate the effect of two types of connector systems in reinforced retaining wall, the centrifugal tests for the conventional connector and new settlement connector system were performed. In the centrifugal tests, the aluminum plate for the face was used and the aluminum foil was used as a reinforcement. The granite soil was adopted as a fill. As a result, The settlement reinforced retaining wall reached to the failure at 80g-level. In contrast, the conventional reinforced retaining wall was collapsed at 69g-level. It means that the settlement reinforced retaining wall has the stronger stability than the conventional reinforced retaining wall. In addition, it was shown that the settlement connector system is more effective to release the stress concentration occurred at the face of reinforced retaining wall than the conventional connector system.
Temperature Analysis of PSC Box-girder Bridges Using Inverse Thermal Analysis Program
Park, Min-Seok ; Jo, Byung-Wan ; Lee, Myung-Kue ;
Journal of the Korean Society of Safety , volume 21, issue 4, 2006, Pages 95~101
It is well known that the thermal load in PSC(prestressed concrete) box-girder bridge is the principal cause of detrimental crack. The longitudinal stress caused by the lateral stress from the temperature gradient in slab of PSC box-girder bridge has a considerable influence on the durability and economy of bridge structures. As the basic study for the rational consideration of thermal load and the derivation of design guide, the inverse thermal analysis program for PSC box-girder bridges using field measurement data is developed. In this paper, thermal analyses are performed using field monitoring data for the sample PSC box-girder bridge. It is proposed that the link between monitoring program and the inverse analysis program is available.
A Study on the Risk Rate of Work Type According to the Fatal Accident Cases and the Work Strength in Construction Work
Lee, Jong-Bin ; Go, Seong-Seok ; Jang, Seong-Rok ;
Journal of the Korean Society of Safety , volume 21, issue 4, 2006, Pages 102~107
Construction accidents have not decreased in spite of much effort such as new work methods, education and research related to safety works. Specially, many fatal accidents happened in construction works which involve the apartment, building, school, church, hotel, hospital, bank work and the other works. These accidents are mainly caused by unanticipated risk factors. From these reasons, this study researched fatal accidents which happened in construction works during last 13 years(
) and analyzed the input workers and a work period of construction work. According to the input workers and a work period, the results are as following. During 13years(
), the fatal accidents, related to the construction work, were happened to the 1,977 cases. These results were occupied the 21.32% of the total industry accidents. According to the result of the construction, the fatal accident rate of a concrete form work was the highest rate of 16.24% (321 cases) and a temporary work, a steel frame work was the each rate of 12.39%(245 cases), 10.07%(199 cases). Comparing to other work types, the fatal accident rate of those three work types(concrete form work, temporary work, steel work) was represented highly. We surveyed input workers and work period of construction work site. From the result of survey, input workers of a concrete form work were occupied with 13,720. The risk rate of the work type, which was considered input workers and work period, was represented 0.3622(a steel frame work), 0.1142(a temporary work), 0.0782(a tower crane) and 0.0772(a concrete work).
Study of the Relation Between Work-Related Musculoskeletal Disorders and Job Stress in Heavy Industry
Kim, Yu-Chang ; Bae, Chang-Ho ;
Journal of the Korean Society of Safety , volume 21, issue 4, 2006, Pages 108~113
The Work-Related Musculoskeletal Disorders(WMSDs) have been an rising issue since the 1970s. So many manufacturing companies have been tried to improve the work environments for the control and the prevention of the WMSDs. Specific risk factors associated with WMSDs include repetitive motion, heavy lifting, forceful exertion, contact stress, vibration, awkward posture and rapid hand and wrist movement. But recently it has reported that besides working conditions, job stress is the important hazard causes which lead to WMSDs. This study investigates the relation between WMSDs and Job stress from 1426 workers in Heavy Industry. Job stress was evaluated by Karasek's model. Job stress was associated with job satisfaction. Job demand was associated with the WMSDs, but job control was not associated with the WMSDs. The results can be used to design the management program for the WMSDs and the job stress.
Formulation of Human Modeling and Simulation in the Shipbuilding Industry
Kim, Dong-Joon ; Park, Ju-Yong ; Min, Kyong-Cheol ; Chang, Seong-Rok ;
Journal of the Korean Society of Safety , volume 21, issue 4, 2006, Pages 114~118
Recently, work-related musculoskeletal disorders(WMSDs) is one of the major issues in the shipbuilding industry. The number of injured workers has rapidly increased and demands for workers compensation, improvement of work condition and environment to prevent WMSDs become larger. To protect and reduce WMSDs in the shipbuilding industry, simulation technique which showed it's ability of increasing the manufacturing productivity will be applied, because simulation technique has the evaluation ability for a worker's danger level of production process by human activity analysis. In our research, we modeled worker's attitude and simulated worker's action. We evaluated the caution level, compared and analyzed the difference point of digital human which made on computer and actual worker's attitude to check feasibility of human modeling and simulation in the shipbuilding industry.
A Questionnaire Survey on Utilization and Improvement Guides for Safety Signs in Industrial Fields
Kim, Dong-Ha ; Lee, Joon-Won ; Park, Young-Won ; Lim, Hyeon-Kyo ;
Journal of the Korean Society of Safety , volume 21, issue 4, 2006, Pages 119~126
Though safety signs are important since they transmit hazard information even after diverse accident prevention treatments, their functional effectiveness were never tested in Korea so that even those provided by Occupational Safety & Health Act(OSHAct) could not accomplish their objectives, "effective accident prevention", This research was carried out to understand confronted problems and improvement direction for safety signs provided by OSHAct. For them, current safety signs were analyzed with a semiotic view on one hand, and a questionnaire survey was conducted with safety-related people in industrial fields on the other hand. To summarize problems in semiotic aspects, geometric simplicity of pictograms in safety signs seemed to be so emphasized that they might fail to induce realistic action, and their esthetic sensation seemed to be lower than those of developed countries. And according to present questionnaire survey, it was pointed out that; 1) legal systems related with safety signs were not classified appropriately, 2) safety signs were recognized as difficult to understand and inapplicable to industrial fields, and eventually 3) safety signs were not effectively utilized for industrial accident prevention. Therefore, discussions for improving confronted problems and relation to international standards were added at the end.
Safety Oimate Practice and its Affecting Variables in the Chemical Process Industry
Baek, Jong-Bae ;
Journal of the Korean Society of Safety , volume 21, issue 4, 2006, Pages 127~133
The major purpose of this paper to identify safety climate practices, and to find the affecting variables that influence to the difference in the level of safety climate between plants and employees. And this paper attempted to find the interventions for improving safety climate in the chemical plants. The questionnaires were developed from literature review, especially made by HSE(Health and Safety Executive) in the UK and distributed to managers and workers. The frequency analysis was applied for identifying the level of safety climate. The affecting variables(plant size, accident occurrence, accident experience, injury experience and severity, and length of employment) are tested through analysis of variance(ANOVA). The results of frequency analysis showed that both managers and workers recorded generally high level of safety climate, and the major underlying problems are inadequate H&S procedures/rules, pressure for production, and rule breaking. According to the outcomes of ANOVA, the variable 'length of employment' is the only variable which makes the level of safety climate different. From the survey of safety climate practice, this study finds the level of safety climate and three major underlying problems in safety climate factors of the responded plants, and presents two interventions for improving safety performance. Despite of these outcomes, the applied factors are remained questionable for reflecting as the best ones for identifying safety climate in the chemical industry. In addition, the bias caused by self-report exist in the reliability of the response, and the equivalent size of respondents.