• Journal of the Korean Society of Safety
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• v.27 no.5
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• pp.179-184
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• 2012

This study was performed to find out the measurement criteria of slip resistance from analysis of human gait and slips. Many kinds of slip resistance testers were developed based on mechanical friction testers. But, there are, as yet, no unambiguous slip resistance measurement methodologies and generally accepted safety criteria or safety thresholds for estimating slipping hazard exposures. Also, there are variety of measuring conditions between those testers. The measurement criteria should be tested within the range of human slipping conditions observed in biomechanical studies. It's results should clearly consider whether the devices reflect the human slipping conditions. In this study a dragsled type friction tester, which was constructed in accordance with ISO 15133 basically, was used. Test conditions were set in order to determine the range of measurement criteria. It is shown that drag velocity should be more than 1 m/s, acceleration be more than 10 $m/s^2$, contact time be less than 0.1sec, and contact pressure be within 350~400 kPa.

• Journal of The Korea Institute of Healthcare Architecture
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• v.25 no.3
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• pp.75-83
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• 2019

Purpose: There are no clear criteria for slip performance in the BF certification process, so the evaluator relies on subjective judgments depending on the field situation. Physical criteria for determining the slip performance of various floor finishes are not clear. C.S.R., the only criterion currently being used to check slip performance, may raise questions about its coverage, feasibility and reliability. Method: For an analysis of domestic standards and status, KS L 1001, KS M 3510, and KS F 2375. External standards are analyzed for ADA Standard, ANSI Standard, and BS EN Standard. Analyze the test methods and evaluation criteria of O-Y-PSM, BPT, and the dynamic slip resistance test used in these criteria. It also presents an improvement plan for the rational presentation of standards. Results: To date, various kinds of test methods and measuring devices of the slip resistance coefficient have been developed, but there are not many ways to trust useful results related to user safety. Reliability and thoroughly verified test methods and criteria should be used to assess the slip performance of the floor. In order to improve the standard for the evaluation of slip performance in Korea, the existing standard should first be raised to the same level as the overseas standard, and the application of the discriminatory standard should be applied considering the characteristics and usage patterns of each space. Implication: Currently, Korean standards propose various test methods, but the proper use of test methods, scope and assessment criteria are not established, so improvement of the comprehensive standard is necessary.

• Journal of the Korea Safety Management & Science
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• v.16 no.3
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• pp.317-326
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• 2014

Slips and falls are associated with many public injuries in Korea. It is also estimated that slipping are major contributors to slip, trip and fall injury burden. The primary purpose of the present study is to determine if, and to what extent, the standard could be improved in present environment. In order to fulfill our objective, the regulations in Korea and foreign countries were investigated and reviewed. Many kind of standard, mandatory documents and guideline were also reviewed. And then, regulations, standard, guideline etc. reviewed were compared with each others. Also, some criteria was developed in this study. Standard and criteria developed in this study will help to prevent slip, trip, and fall injuries.

• Earthquakes and Structures
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• v.18 no.2
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• pp.185-199
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• 2020

A computationally-efficient method for multi-criteria optimisation is developed for performance-based seismic design of friction energy dissipation dampers in RC structures. The proposed method is based on the concept of Uniform Distribution of Deformation (UDD), where the slip-load distribution along the height of the structure is gradually modified to satisfy multiple performance targets while minimising the additional loads imposed on existing structural elements and foundation. The efficiency of the method is demonstrated through optimisation of 3, 5, 10, 15 and 20-storey RC frames with friction wall dampers subjected to design representative earthquakes using single and multi-criteria optimisation scenarios. The optimum design solutions are obtained in only a few steps, while they are shown to be independent of the selected initial slip loads and convergence factor. Optimum frames satisfy all predefined design targets and exhibit up to 48% lower imposed loads compared to designs using a previously proposed slip-load distribution. It is also shown that dampers designed with optimum slip load patterns based on a set of spectrum-compatible synthetic earthquakes, on average, provide acceptable design solutions under multiple natural seismic excitations representing the design spectrum.

• Journal of the Korean Society of Safety
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• v.27 no.5
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• pp.185-189
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• 2012

While there is no standards on slip risk for contaminants on surface, glycerol is described in standard contaminant for measuring coefficient of friction(COF) and slip resistance such as ISO 13287. But that is just used to measure the slip resistance of surface materials and shoes not to evaluate the contaminant materials. Therefore the objective of this study was to find out the relationship between standard contaminant and the contaminants used usually at the workplaces. For this, some measurement criteria were acquired from the analysis based on biomechanics and kinetics of human gait during slips. The slip resistance according to viscosity of the contaminants was measured applying the criteria and slip probability was determined by the gait analysis. Some factors which should be considered when measuring the slip resistance were identified. The velocity, acceleration, contact time and contact pressure should be 1 m/sec, 10 $m/sec^2$, 350 kPa and less than 0.5sec respectively. The variation of viscosity according to temperature for working oils was different from that of standard contaminant. The static coefficient of friction (SCOF) of working oils was almost 0.5 times as large as the SCOF of standard contaminant. So it was assumed to be difficult to compare the contaminants at the workplaces with the glycerol as a standard contaminant for estimating the slip risk.

• Tribology and Lubricants
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• v.21 no.1
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• pp.16-20
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• 2005

Friction and wear characteristics between two steel surfaces under fretting condition are investigated experimentally. The fretting damage caused by low-amplitude oscillatory sliding can be classified into three regimes of gross-slip, mixed-slip and partial-slip due to stick-slip phenomenon. One of the most important characteristics of fretting wear is the transition from gross-slip to mixed-slip. This study was focused on getting the degree of stick-slip out of the friction transition under fretting condition. Fretting wear is divided into three conditions of gross-slip/mixed-slip/partial-slip. The criteria for the division are friction and displacement amplitude, wear scar morphology and dissipated energy. In this test, friction force and displacement were measured for detecting the transition from mixed-slip to gross-slip and qualitatively predicting the degree of the wear.

• Proceedings of the Safety Management and Science Conference
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• 2013.04a
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• pp.19-29
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• 2013

Slips and falls are associated with many occupational injuries in Korea. It is also estimated that slipping are major contributors to slip, trip and fall injury burden. So "LOCAL RULE ON OCCUPATIONAL SAFETY AND HEALTH STANDAR D" must be improved, especially article 3(prevention of slip, trip and fall). The primary purpose of the present study is to determine if, and to what extent, the standard could be improved in present environment. In order to fulfill our objective, the another regulation in Korea and foreign countries were investigated and reviewed. Many kind of standard, mandatory documents and guideline were also reviewed. And then, regulations, standard, guideline etc. reviewed were compared with each others. The article 3 was revised as below. 1. The floors of the traffic route in workplace shall have no hole or slope, or be uneven or slippery so as, in each case, to expose employees to slip, trip and fall risk, except if adequate measures have been taken to prevent a employees falling. 2. The employer shall design, install and fix the drain for effective drainage if fluid contaminants were frequently occurred. So far as is reasonably practicable, An employer shall keep the workplace clean, sanitary, and dry so that employees won't have any risk to tripping or slipping at the workplace. 3. To facilitate cleaning, every floor, workplace, and passageway shall be, so far as is reasonably practicable, kept free from protruding objects, splinters, holes, etc. Also, some criteria was developed in this study. Standard and criteria developed in this study will help to prevent slip, trip, and fall injuries.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.5
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• pp.847-854
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• 1989

Axial force of a V-belt CVT is investigated experimentally. The experimental results on speed ratio-torque-axial force show good agreement with the theoretical results that were obtained in the previous work. It is also found that torque capacity of the V-belt CVT increases as the axial force and the speed ratio increase. Impending slip which occurs at the maximum torque is determined via experiments for various speed ratios. Based on the impending slip region, and the theoretical curves for the speed ratio-torque-axial force relationship, an actual operating criteria for the V-belt CVT is obtained. It is suggested to use the actual operating criteria with the theoretical equations as a basic design formula for the V-belt CVT.

• Journal of the Korean Society of Safety
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• v.25 no.6
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• pp.65-69
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• 2010

This paper presented an experimental study of slip resistance characteristics of shoes and floor surface contact with special focus on the effect of surface roughness, outsole material and mechanical abrasion. The factors that affected the results of slip resistances were investigated for four kinds of rubbers and five kinds of floor samples using the VIT(English XL) tribometer. The slip resistance was observed to increase gradually with increasing roughness for five kinds of floor roughness. In the higher surface roughness (larger than $11.5{\mu}m$), the slip resistance increased more rapidly and exceeded safety criteria at $22.60{\mu}m$. The slip resistance was observed to decrease with increasing hardness of outsole, except for butylenes rubber, which seemed to show the material property. The slip resistance decreased with number of trials. In the first several times(5 or 6 trial), the slip resistance decreased more rapidly, whereafter it approached gradually constant value. The slip resistance of surfaces has generally been shown to increase with floor surface roughness and to decrease with hardness of outsole and number of trials under the wet condition.

• Journal of the Korean Mathematical Society
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• v.53 no.3
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• pp.597-621
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• 2016

We present regularity conditions for suitable weak solutions of the Navier-Stokes equations with slip boundary data near the curved boundary. To be more precise, we prove that suitable weak solutions become regular in a neighborhood boundary points, provided the scaled mixed norm $L^{p,q}_{x,t}$ with 3/p + 2/q = 2, $1{\leq}q$ < ${\infty}$ is sufficiently small in the neighborhood.