• Fire Science and Engineering
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• v.31 no.1
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• pp.58-62
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• 2017

There is a growing need for seismic resistance design. But it is controversial that standards of sway brace device in non-structural elements for buildings like pump waterway is vary widely. Therefore, in this study to get a valid range of sway brace device in seismic resistance design, using load test of sway brace device. As a result, load of safe range from 0 to 18.5 kN and under 29.4 kN, no structural fault of sway brace device. And using internet of things get a data of seismic resistance design from sensor node like accelerometer, GPS, tilt sensor and temperature sensor through steps of sampling and prediction. These results will be acceptable for monitoring system for seismic resistance in non-structural elements.

• Journal of the Society of Disaster Information
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• v.18 no.3
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• pp.646-659
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• 2022

Purpose: In this study, we developed a 4-way sway prevention brace that efficiently reduces the installation area and has excellent stability and seismic performance compared to the conventionl sway prevention brace used in existing firefighting facilities. The performance and reliability of the developed 4-way way prevention brace were analyzed by the tensile, compression tests and seismic tests. Method: As the static test, 4-way sway prevention braces were installed on the horizontal and vertical pipes to perform the tensile and compression tests based on the KFI certification standard and the maximum movement was measured at the rated load. As a dynamic test, 4-way sway prevention braces were installed in the pipes filled with water, and the test response spectrum to the input excitation wave were measured through the acceleration sensors. After the seismic tests, separation, failure, and local deformation of the pipes, and 4-way sway prevention braces were not observed. Result: The results of the tensile and compression tests indicated that the maximum movement of the pipe during tension and compression was 50% to 70% or less compared to the certification values, indicating that the performances of the 4-way sway prevention braces were very excellent. The results of the the seismic tests indicated that the test response spectrum of the 4-way sway prevention braces is within the required response spectrum. Conclusion: In this study, it was found that the 4-way sway prevention braces satisfied the KFI certification standard and were superior compared to the existing sway prevention brace in terms of the stability, cost, and installation area.

• Journal of the Korea Safety Management & Science
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• v.26 no.1
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• pp.9-14
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• 2024

Restraints of Branch Lines are used as earthquake-resistant support devices for fire-fighting pipes along with sway brace devices. The central types are aligned and fixed in a straight line with center of the pipe, but the eccentric types are fixed to on side of the pipe, so a bending moment occurs. In this study, three specimens each of central type and eccentric type were installed at an angle of 45° from the vertical and a monotonic compression load of 1340N was applied. All central type samples satisfied 17.8mm of the allowable displacement, but all eccentric type samples failed to meet the target load and buckled. Therefore, when considering the performance of eccentric type restraints, both compressive load and bending moment must be considered. Even through material mechanics calculations, the yield stress of eccentric type - 3/8 inch all threaded steel bolt - exceeds 320Mpa of the allowable stress. A experiment standards need to be established for eccentric type restraints.

• Fire Science and Engineering
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• v.34 no.1
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• pp.47-54
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• 2020

This paper proposes a solution to the problems of constructing and installing sway braces for existing standpipes in narrow spaces and pits. The study develops a floor-fixed sway brace for a narrow space that can support the ground area under horizontal seismic loads (X-axis, Y-axis) as well as vertical seismic loads (Z-axis). The results of structural analysis using SolidWorks simulation showed that the eccentric load was generated in the first design according to the anchored position along the vertical direction, and the problem of exceeding the allowable stress of the material along the horizontal and vertical directions. In the second design model, deformation caused by the eccentric load along the vertical direction, similar to the first design model, did not occur. The maximum strain rate was 0.17%, which is approximately 12.84% less than the first design model (Maximum strain rate of 13.01%). It was confirmed that the structural stability and durability improved. Compressive and tensile load testing of the prototypes showed that all of them meet the performance criteria of the standard.

• PNF and Movement
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• v.21 no.1
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• pp.27-35
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• 2023

Purpose: Hallux valgus (HV) is one of the most common chronic foot disorders, occurring when the first toe deviates laterally toward the other toe. HV impairs muscle strength and affects gait function (postural sway and gait speed). Thus, this study aims to investigate using the FDM system the effect of wearing braces on gait while wearing a virtual reality (VR) device. Methods: This study was conducted on 28 healthy adults with HV of 15 degrees or more. To compare differences in walking, depending on whether a toe brace can be worn, the subject walked without wearing anything, walked after wearing the VR device, and walked after wearing the VR device and the toe brace, and the FDM system was used for the gait ability measurement analysis. Results: As a result of a one-way repeated analysis of variance, the walking speed-related variables (cadence, velocity, etc.) in the HV group were higher during comfortable walking. In addition, walking while wearing a VR device and walking while wearing a VR device and a toe brace demonstrated more significant values in terms of six gait parameters (double stance phase, loading response, stage, stage, stage, and stage). The maximum pressure of the forefoot was significantly reduced when walking while wearing a VR device and a toe brace compared to comfortable walking, but in all variables, there was no statistically significant difference between walking while wearing a VR device and walking while wearing a VR device and a toe brace. Conclusion: Orthosis with a VR device during gait (OVG) and gait with a VR device (GVR) affect gait in HV patients. However, there was no significant difference between GVR and OVG. Thus, it is necessary to conduct experiments on various HV angles and increase the duration of wearing the toe brace.

• Fire Science and Engineering
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• v.33 no.5
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• pp.140-148
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• 2019

In line with the "mandatory seismic design of fire protection facilities," development of design automation software is indispensable for improving the reliability and efficiency of seismic design. The seismic design automation software developed in this study is an automated S/W for seismic design of fire-fighting facilities, and functions such as automatic arrangement of anti-shake braces according to Korea National Fire Agency's Seismic Design Standards for fire-fighting facilities, output of seismic bracing calculation bills and automatic quantities counting. In addition, the seismic design automation software not only reduces the work speed by three times compared to the manual design of the designer, but also improves the reliability of the design by reducing the human error related to the design quantity such as the brace. In addition, in the seismic design method of fire protection facilities that have been approached conservatively, it was possible to perform the optimal seismic design by using computer algorithms for at least in the use of braces.