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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society of Safety
Journal Basic Information
Journal DOI :
The Korean Society Safety
Editor in Chief :
Volume & Issues
Volume 10, Issue 3 - Sep 1995
Volume 10, Issue 2 - Jun 1995
Volume 10, Issue 1 - Mar 1995
Selecting the target year
A Study on the Safety Evaluation of Design for Piping Materials (I)
Journal of the Korean Society of Safety , volume 10, issue 2, 1995, Pages 3~9
Several piping material test methods have been developed as a result of advances in elastic-plastic fracture mechanics. It's known that, crack propagation of the materials strongly governed by the
value. But the value is still difficult to be obtained because of it's complicate and troble-some determination process. In this paper, to prove the validity of the developed test procedure a series of tests were peformed at various temperatures and for different material directions. directions.
A Study on Evaluation Method of Fatigue Strength Data Using Likelihood Interval Estimation Method
Journal of the Korean Society of Safety , volume 10, issue 2, 1995, Pages 10~16
In estimating the fatigue data, only the uniform safety rate has been applied so far However, since more reasonable design concepts such as machine structures or subsidiary materials will be required in the future, the importance of a statistical estimation method for fatigue data is being highlighted. With such basic conception in mind, this study was aimed at critically discussing the interval estimation method which has been applied using the classical statistics thus far It was conceived that this conventional method would result in the estimation of the unstable side from the viewpoint of the likelihood Interval estimation method. In this regard, this study aimed at estimating the fatigue strength through the likelihood interval estimation method comparing it with the conventional interval estimation method would result in the estimation of the unstable side from the viewpoint of the likelihood interval estimation method. One of the methods using the likelihood for estimation data is the Bayes method. Based on this theory, statistical estimations were positivly applied, and thereupon, the fatigue data were estimated.
A Study on the Influence of Redistributed Residual Stresses on Fatigue Crack Growth Behaviors in the Welded Plate with Various Thickness
Journal of the Korean Society of Safety , volume 10, issue 2, 1995, Pages 17~23
Though the magnitude is decreasing, the compressive residual stress is always distributed during fatigue crack growth near the crack tip. This means that the residual stress is released during fatigue crack growth due to the alternative load.
is modified by using the initial residual stress and the redistributed residual stress in uniform and various thickness welded specimens. The former is denoted by
and the latter is denoted by
gives more accurate relations in da/dN vs.
curve, however the difference is very small.
A Study on Durability Test Method of Vehicle Suspension Systems
Journal of the Korean Society of Safety , volume 10, issue 2, 1995, Pages 24~31
This paper shows the fatigue durability test method for vehicle suspension systems. Durability should be assured for the safe driving during vehicle life cycle. A computer simulation for the vehicle dynamics was used to obtain dynamic loads that were required for the fatigue durability test. Durability tests were done for an Important load-carrying component of the suspension system. Stress analyses using stresscoat and strain gages were also done for the component. This study demonstrated an effective method for the fatigue durability test.
A Study on Sound Attenuation by Structure Improvement of Silencer for Exhaust Fan
Journal of the Korean Society of Safety , volume 10, issue 2, 1995, Pages 32~38
The silencers are used to attenuate noise generated by the exhaust fan for industrial processes. The types of silencers applied in this study are absorptive duct silencer, expansion chamber, absorptive chamber and resonator. This study was carried out to verify the attenuation by the various silencers and elements. As a result, the difference of attenuation between the calculation and the measurement was about 1-7㏈. The attenuation by absorptive duct silencer and absorptive chamber was negligible at frequencies below 250Hz. The expansion chamber should be used for low frequency applications where the absorptive duct silencer was Ineffective. The attenuation by resonator may be realised when the ratio of frequency to resonant frequency approaches 1.
Study About a New Propulsion System Using CRP(II) (Noise and Flow of the Counter-Rotating Propeller)
Journal of the Korean Society of Safety , volume 10, issue 2, 1995, Pages 39~45
Three-dimensional flow measurements were conducted between the rotors of the CRP To understand mean flow phenomena of the CRP's, the results of the three-dimensional measurements were shown. Interaction noise of the CRP, which increases the overall ,level of sound pressure In the new propulsion system, is documented by using the double conditional sampling technique. The rear rotor will increase the axial flow between the rotors of a CRP depending upon the relative locations between the forward and the rear rotor blades. The decay and spreading of the forward wakes and the upstream propagation of the rear blade disturbances are shown along with the interaction of the flow disturbances by the two rotors of blades.
A Study on the Effective Cutting Conditions of Cage Motor Rotor Considering Production Rate (II)
Journal of the Korean Society of Safety , volume 10, issue 2, 1995, Pages 46~55
The recent development of NC lathe and machining center have enabled automatic or unmanned manufacturing system for the improvement of production rate. And if you want to introduce automatic or unmanned manufacturing system into the cutting process of cage motor rotor, the selections of effective cutting conditions, rational tool grades and tool angles are necessary. As a result, the selection of cutting conditions, tool grades and tool angles are important factors to production rate.
Numerical Prediction of Contaminant Dispersion within the Laminar Flow Field using FDM
Journal of the Korean Society of Safety , volume 10, issue 2, 1995, Pages 56~63
A simulation of contaminant dispersion in a water reservoir has been done using 2-D finite difference method(FDM). The steady state velocity field of the reservoir was computed using stream function-vorticity formulation of Wavier-Stokes equation and continuity equation. Based on the computed steady state velocity field, the transient convective diffusion equation of the contaminant dispersion was computed. For the 1m
1m reservoir model with inlet and outlet attached, it was shown that the center of circulation located toward right. For the numerical values of v =0.01(
/s) and D=0.6(
/s) and the flow of 50(
/s ), it was determined that the outflow had to be shut down in 18 seconds to prevent from severe pollution. Also the required time was computed to be 6 seconds for the inflow of 100 (
/s). The result of this study is considered, hopefully, to be useful for the design of the water reservoir systems that are the subjects to various contamination.
An Experimental Study on the Thermal Shock Behavior of PC/PET Alloy
Journal of the Korean Society of Safety , volume 10, issue 2, 1995, Pages 64~71
Tests were performed to evaluate the effect of thermal shock behavior on the mechanical properties of PC(poly-carbonate) and PET(polyethylene-terephthalate) with MBS(methylmethacrylate-butadiene-styrene) alloy. Five different material weight fraction for PC/PET were employed : 0/100, 25/75, 50/50, 75/25, and 100/0. Three different weight fraction of MBS were added to each PC/PET : 0, 3, and 9. Therefore fifteen different types of PC/PET/MBS were prepared using single screw extrude. and injection molding machine. One thermal shock cycle consisted of each one hour stay at -
chamber without delay. Specimens were thermal shocked up to 20 and 40 cycles. Specific mechanical properities considered in this study include tensile, izod impact, and high rate Impact behaviors. In addition, the morphology of the fractured surface after Izod impact testing was investigated by the SEM (scanning electron microscope).
A Study on Characteristics of De-electrification and Discharge of Self-Discharged Electrostatic Reducer
Journal of the Korean Society of Safety , volume 10, issue 2, 1995, Pages 72~76
An electrostatic passive neutralizer without HV power source has been used widely to reduce charges on insulators such as running plastic films, papers and cloths, but its elimination characteristics and safely have been hardly investigated in detail. Especially, an operation of the passive neutralizer depends primarily on the charged insulator and the elimination ability does not depend on only the neutralizer, because an electrostatic elimination is caused by corona discharges occurring between the passive neutralizer and charged insulator. From a reason described above, the purpose of this study is to examine experimentally the elimination ability of the passive neutralizer. Experiments were made on the corona discharges between the passive neutralizer and charged insulator running at high velocity in practical field to make clear the setting condition of the passive neutralizer for operating effectively and safely. Results obtained from field experiments are presented in this paper.
A Study on Characteristics of a Volatage-Applied Electrostatic Reducer
Journal of the Korean Society of Safety , volume 10, issue 2, 1995, Pages 77~83
An electrostatic reducer of a multi-pole high DC voltage applied type and a high frequency square wave voltage applied type have been studied to eliminate effectively and safely electrostatic charge on a dummy charged material. As a fundamental experiments, measurement were made on the decay time as a function of distance between electrostatic reducer and charged body, skewed angle of electrostatic reducer installed and wind speed of generated ions(＋ or －) by electrostatic reducer with high DC voltage and high frequency square wave voltage. Based oil the results above, a appropriate installation and method were produced as a trial for factory.
A Study on the Autoignition of Granulated Activated Carbon with Change of Oxygen Concentration
Journal of the Korean Society of Safety , volume 10, issue 2, 1995, Pages 84~91
The characteristics of critical spontaneous ignition of granulated activated carbon were investigated In atmospheres of differing oxygen concentration. At the same concentration the larger vessels yielded the lower critical spontaneous ignition temperature. At the same vessel, as the concentration of oxygen was reduced, Ignition occurred later and at higher ambient temperature, and critical spontaneous ignition temperature increased. The apparent activation energy calculated from the Frank-Kamenetskii's ignition theory appeared to be the slight different value respectively and the mean apparent activation energy was 19850㎈/㏖.
A Study on the Flash Point Determination of Toluene-o-Xylene and Toluene-Methyl Ethyl Ketone Mixtures by Air-Blowing Method
Journal of the Korean Society of Safety , volume 10, issue 2, 1995, Pages 92~96
The flash point is generally used as a hazardous index of fire or explosion of a flammable liquid. In this study, the lower flash points and the upper flash points according to the composition of Toluene-o-Xylene and Toluene-Methyl Ethyl Ketone mixtures are determined by air-blowing method. As results, relations between the flash points and the compositions of mixtures ; (1) for Toluene-o-Xylene mixtures
＋40.50 (2) for Toluene-Methyl Ethyl Keton mixtures
Construction of Expert System for Hazard Assessment of Unconfined Vapor Cloud Explosion
Journal of the Korean Society of Safety , volume 10, issue 2, 1995, Pages 97~104
To evaluate readily the effect of unconfined vapor cloud explosion(UVCE) having high possibility of accident and risk in chemical industries, the expert system of UVCE was developed and its applicability on a real accident was analyzed. We found that the hazard of UVCE could be well evaluated from the TNT equivalency model and the empirical loss data produced by overpressure for chemical facilities. By using the developed expert system, the size of vapor cloud, the quantity of vaporization, the released energy, the overpressure range from explosion point, and the impact damage of each installation could be estimated respectively. Also, probable maximum loss and catastrophic loss potential for real accident( cyclohexane release in Flixborough Nypro company) were estimated and compared with damages of the accident. As a result, the developed expert system could be well applicable to real accident.
A Study on the Development of Long Term Exposure
Journal of the Korean Society of Safety , volume 10, issue 2, 1995, Pages 105~112
The concentrations of
were measured to estimate a new developed long term exposure
sampler at Pusan City considering the meteorological factors from May to July, in 1994. The monthly mean concentration of
was 15.9 PPb and 36.2
and their high values were shown in the downtown of Pusan City which show potential pollution due to the increase of traffic activities and micrometeorological factors In and around the City. As a result of statistical correlation between
concentration by new sampling method and
concentration by the handy air sampler and chemiluminescent nitrogen oxides analyzer, 1994, correlation coefficients were high(r=0.93) and showed more than 0.88 value in the high concentration data set, which was arbitrarily divided into 30
concentration in an attempt to further investigate these relationships. Therefore, use of new developed long term exposure
sampler is good for
measurement and valuable for estimation of air quality in the urban and Industrial area.
A Study for Maximal Force Exertion on Upward Slopes
Journal of the Korean Society of Safety , volume 10, issue 2, 1995, Pages 113~119
Many studies have been done to determine the magnitudes of force a man can exert on the objects. However, very little attention has been paid to those In postures on slopes. This paper was aimed to evalute how human work postures would affect the push/pull force and to grasp the relationships between the rectified EMG(REMG) measured at the trunk muscles and force exerted on upward slopes. Two subjects participated in the experiment. The results showed no lineal relationship between the REMG and exerted force at handle. But as the slope and handle height increased, exerted force and muscular stress on erector spinae or rectus abdominis were generally increased. It was notified that since ANOVA did not detect any statistical significance in REMG variation due to dominant muscles, careful application and interpretation of the REMG should be required in analyzing maximal force exertions.
The Evaluation of Safety and Remaining Life on Fracture and Fatigue in Rail Steel
Journal of the Korean Society of Safety , volume 10, issue 2, 1995, Pages 120~128
The fatigue failure of rail is a principal source of derailment accidents. The reduction of fatigue failures can be achieved by Intensive track maintenance and periodic safety assessments for the railway. For the safety assessments, it is required to have more accurate knowledge for fatigue behavior such as the crack initiation, propagation, crack growth rate and the remaining service life in rail. In this paper, the mean stress effects for the fatigue behavior of rail steel are studied. For this study, the fatigue test is conducted and some equations for fatigue evaluation are applied and compared. From the results, we can see that the fatigue crack growth rate is the more increased as the men stress Is the more increased, the mean stress effect is represented well by the combination of stress intensity factor range and maximum stress intensity factor and Crooker and Range's equation represented by
is the best fit for fatigue evaluation and safety assessment of rail.
A Finite Difference Large Displacement Analysis of Rectangular Thin Glass Plate
Kim, Chi-Kyung ;
Journal of the Korean Society of Safety , volume 10, issue 2, 1995, Pages 129~133
A new approach to the analysis of thin. rectangular window giass glass supported on flexible gaskets. and subjected to uniform lateral pressures was evolved. Based on the Von Karman theory of plates and using the finite difference method. a computer program which determines the deflections and stresses in simply supported thin glass plates was developed.