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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 8, Issue 4 - Dec 1993
Volume 8, Issue 3 - Sep 1993
Volume 8, Issue 2 - Jun 1993
Volume 8, Issue 1 - Mar 1993
Selecting the target year
Structural Reliability Analysis of Automatic Fire Detectors for Reduction of False Alarms
Journal of the Korean Society of Safety , volume 8, issue 1, 1993, Pages 6~12
Now it is reported that there are many companies and factories which confront to the problem of false alarm in Automatic Fire Detecting System (AFDS). Though an AFDS is a high-priced and very important device in detecting a fire. the problem degrades the reliability and utility, eventually faith. of the system. This is a research concerned about the problem of false alarm of fire detectors in an AFDS. Structure of detectors was modeled up as a general K out-of n system. and reliability characteristics including false alarm rate and missed alarm rate, are derived from it. For decision of an optimal structure of detectors. preliminary analysis on various criteria is accomplished. It is concluded that appropriate modification of a detector with plural sensors may increase the system reliability and decrease the false alarm rate.
A Study on the Fatigue Crack Propagation of Partly Heat Treated Medium Carbon Steel
Journal of the Korean Society of Safety , volume 8, issue 1, 1993, Pages 13~20
It is well known that mechanisms of fracture and fatigue crack propagation depend upon various characteristics such as environmental condition. crack geometry. heat treatment and mechanical properties. It seems to be important for the detailed evaluation of structural integrity to investigate the effects of the above factors on the behavior of structural components which contain flaws. In this paper. it is studied that the fatigue crack propagation of partly heat treated medium carbon steel (SM45C) by high frequency heat treatment.
Programming for the Structural Analysis of Form Structure
Journal of the Korean Society of Safety , volume 8, issue 1, 1993, Pages 21~28
Occupational Safety & Health Code requires to calculate Design Load and stress for the approval within thirty working days prior to initiating each construction site work This study is to develop an easy and useful program that each safety manager. Controller or engineers are able to make output for the above mentioned form structure analyses without knowledge or engineering background of it. Therefore. three, randomly selected. different major student and engineers verified if they could make output. really without the engineering background. And then some deficiencies are corrected after finding those from the program operation.
Study on Effective Treatment of Waste Gases in Chung-Ju Industrial Complex with Polymeric Absorbent( II )
Journal of the Korean Society of Safety , volume 8, issue 1, 1993, Pages 29~34
Two major hazardous gases. SOx and NOx. are emissioned from fossile fuels. SOx has been removed when oil is refined but NOx hasn't. So NOx is very serious problem in air pollution now There are several technologies to remove NOx. e.g. cooling method. scrubbers method. combustion method, polymer membrane method and adsorbent methods. Polymer membrane and adsorbent methods have good economic merit in removal systems of low content hazard gases. Traditional absorbents are porous silicas, aluminas. active carbon and zeolites. But these absorbents act only physisorption which has less removal performance than chemisorption. In this study. polymeric absorbent which has chemisorption as well as physisorption was analyzed about chemical structure and experimented about optimum operation conditions. The results showed that the chemical structure of the polymeric absorbent was expected as polystyrene having -N-CH
COOH absorbent was revealed about 310
/g. The molar ratio of absored NO to charged NO in absorption experiments was shown 60% of the polymeric absorbent and 45% of zeolite absorbent at 3
Chemical Risk Assessment of Oxidizing Substances
Journal of the Korean Society of Safety , volume 8, issue 1, 1993, Pages 35~46
This paper was concerned with the risk assessment about oxidizing substances as dangerous goods by burning test method. The sample. which was formed with the heaped cone-shape. was composed of solid oxidant and sawdust. The burning time of each sample was measured under the following various conditions circumstance temperature. mixing ratio of oxidizing substance and sawdust. particle size of sawdust and kinds of sawdust. As a results. the effective combustibility was gained when the sawdust content was 20∼30 wt.% in the sample and the lauan with -30+50 mesh was used. But. although the circumstance temperature increased. burning efficiency of the samples wet
e not affect by it. Finally. the average burning times were obtained by considering the weighting factors related on the mixing ratio and the circumstance temperature. And then. it were compared with the combustion risk level and the effects of cation and anion of oxidizing substances as dangerous goods.
A Study on the Analysis of Overload of a Two-Span Continuous Bridige
Journal of the Korean Society of Safety , volume 8, issue 1, 1993, Pages 47~53
Residual Deformation Analysis(RDA) is a new method for ratings of the continuous bridges. The RDA makes it possible to expand the inelastic steel girder bridge design method set forth in the American Association of State Highway Officals'(AASHTO) Guide Specifications for Alternate Load Factor Design Procedures for Steel Beam Bridges Using Braced Compact Sections(1986) into an inelastic rating method. It is a method to assess the residual moments and deformations that are set up in a beam that has been loaded into the post-elastic range This method combines classical elastic conjugate beam theory with linear moment-rotation relationships for midspan inelastic positive moment. The limit state is inelastic serviceability limit. which is defined as the ratio of the span to midspan inelastic deflection(C=L/D).
Fatigue Growth Behavior of Short Cracks
Journal of the Korean Society of Safety , volume 8, issue 1, 1993, Pages 54~58
The fatigue growth behavior of short cracks were studied various load ratios. Computer-aided unloading elastic compliance method was employed to measure the closure and the length of short cracks. In the dc/dN-
K relationships. the decreasing behavior of the growth rate of short cracks is due to the decrease of crack opening ratio with increasing crack length. Irrespective of load ratio. the growth rate of short cracks can be well decribed in terms of the effective stress intensity factor range
, which is calculated on the base of crack closure. dc/dN-
relationships of short cracks are found to coincide well with the corresponding long crack relationships. accordingly. the growth rate of short cracks can be predicted using that of long cracks.ort cracks can be predicted using that of long cracks.cks.
A Study on the Fatigue Fracture Behavior of Heat Cycle of Welded Dissimilar
Journal of the Korean Society of Safety , volume 8, issue 1, 1993, Pages 59~63
It is very difficult to find not only optimized welding condition but also fatigue characteristics of the dissimilar weld. In this study. Low carbon steel (SS41) and austenitic stainless steel (STS304) were welded by GTAW welding with STS309 stainless wire rod and Single Edge Notch specimens were used for the examination of fatigue behavior on welding heat cycle. The fatigue crack growth rate in HAZ of SS41 was the highest. The second was in STS304 bond line and the lowest was in HAS of STS304.
Safe Speed Limit of Robot Arm During Teaching and Maintenance Work
Journal of the Korean Society of Safety , volume 8, issue 1, 1993, Pages 64~70
Serious injuries and deaths due to multi-jointed robot occur when a man mispercepts. especially during robot teaching and maintenance work. Since industrial robots often operate with unpredictable motion patterns, establishment of safe speed limit of robot arm is indispensable. An experimental emergency conditions were simulated with a multi-jointed robot. and response characteristics of human operators were measured. The result showed that failure type, robot arm axis. and robot arm speed had significant effects on human reaction time. The reaction time was slightly increased with robot arm speed. though it showed somewhat different pattern owing to failure type. Furthermore the reaction time to the axis which could flex or extend. acting on a workpiece directly. was fastest and its standard deviation was small. The robot arm speed limit securing a‘possible contact zone’based on overrun distance was about 25cm/sec. and in this sense the validity of safe speed limits suggested by many precedent researchers were discussed.
A Study on the Influece of Residual Stresses on Fatigue Crack Growth Behaviors in the Weldment Plate with Various Thickness
Journal of the Korean Society of Safety , volume 8, issue 1, 1993, Pages 71~79
The welding implementation used widely in the industrial field is gradually increasing due to weight reduction. unlimited material thickness. simplified structure design. and 1 manufacturing time and cost reduction. The most significant factor that influences the fatigue crack growth rate is the residual stress generated during the welding process. Many researchers have studied the effect of the residual stress on crack growth behavior. Through a fatigue test in a various-thickness welded specimen. redistributed residual stress is measured as the crack is developed. Then. by superposing the measured residual stress on the K value obtained by the finite element method.
Seismic Behavior of A 2/5-Scale Steel Structure with Added Viscoelastic Dampers
Oh, Soon-Taek ;
Journal of the Korean Society of Safety , volume 8, issue 1, 1993, Pages 80~87
This paper summarizes an experimental and analytical study on the application of viscoelastic dampers as energy dissipation devices in structural applications. Shaking table tests are carried out on the viscoelastically damped structure and the obtained structural responses are compared to those of the inelastic analysis results for the same test structure with no dampers added. It can be concluded the viscoelastic dampers are effective in reducing excessive vibrations of structures under strong earthquake ground motions. It is also observed that the increase in structure's stiffness by the addition of dampers can not contribute to improving the seismic response of a structure. In general. the reduction of the seismic response by adding the dampers to the structure is mostly resulted from the increased damping effect. It is found that the modal strain energy method can be used to reliably predict the equivalent structural damping. and the seismic response of a viscoelastically damped structure can be accurately estimated by conventional modal analysis techniques.