• Title, Summary, Keyword: 헬멧

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Finite Element Analysis on the Stress and Deformation Behaviors of a Safety Helmet (안전헬멧의 응력 및 변형거동에 관한 유한요소해석)

  • Kim, Chung-Kyun
    • Journal of the Korean Institute of Gas
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    • v.13 no.4
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    • pp.27-32
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    • 2009
  • This paper presents the stress and deformation behaviors using the finite element method as a function of the thickness of the helmets without the bead frames on the top of the shell structure. The helmet that would provide head and neck protections without causing discomfort to the user when it was worn for long periods of time should be manufactured for increasing the safety and impact energy absorption. The FEM computed results show that when the impulsive force is applied on the top surface of a helmet, the maximum stress and strain have been occurred around the position of an applied impact force, which may lead to the initial failure on the top surface of the helmet shell. As the helmet thickness is decreased from 4mm to 2mm, the impact energy absorbing rate is radically increased, and the maximum stress of the helmet is increased over the tensile strength, 54.3MPa of the thermoplastic material. Thus, the top surface of the helmet should be supported by a bead frame and increased thickness of the shell structure.

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Design and Evaluation of Intelligent Helmet Display System (지능형 헬멧시현시스템 설계 및 시험평가)

  • Hwang, Sang-Hyun
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.45 no.5
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    • pp.417-428
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    • 2017
  • In this paper, we describe the architectural design, unit component hardware design and core software design(Helmet Pose Tracking Software and Terrain Elevation Data Correction Software) of IHDS(Intelligent Helmet Display System), and describe the results of unit test and integration test. According to the trend of the latest helmet display system, the specifications which includes 3D map display, FLIR(Forward Looking Infra-Red) display, hybrid helmet pose tracking, visor reflection type of binocular optical system, NVC(Night Vision Camera) display, lightweight composite helmet shell were applied to the design. Especially, we proposed unique design concepts such as the automatic correction of altitude error of 3D map data, high precision image registration, multi-color lighting optical system, transmissive image emitting surface using diffraction optical element, tracking camera minimizing latency time of helmet pose estimation and air pockets for helmet fixation on head. After completing the prototype of all system components, unit tests and system integration tests were performed to verify the functions and performance.

A study on the needs for the cool motorcycle helmet and the factors affecting the purchasing intention (오토바이용 쿨 헬멧의 필요성과 구매요인에 관한 조사연구)

  • Seong, Deokhyun;Kim, Jongsoo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.12
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    • pp.8386-8393
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    • 2015
  • This study is to investigate the needs for the cool motorcycle helmet and the factors affecting the purchasing intention of cool helmet. The convenient sampling from motorcycle clubs were conducted during 5/20/2014~5/28/2014 on Google DAX. As a result, 197 participants were surveyed. The main reasons of sensing unpleasant feeling wearing helmet were identified as 'hot and uncomfortable feeling' and 'it ruins hair style'. The mean score expressed in terms of five point scale showed that the needs for cool helmet was 3.9 and the purchasing intention of cool helmet was 3.6, respectively. The significant factors influencing the purchasing intention of cool helmet were identified as 'the needs for cool helmet' (odds ratio=6.52) and 'extra paying intention for cool helmet' (odds ratio=1.77). The main reasons of sensing unpleasant feeling wearing helmet were similar to the previous research. However, we can expect that the initial target market for cool helmet would be the low end (less than \40,000 of extra paying intention) or the high end (more than \100,000 of extra paying intention). The main contribution of this study is dealing with the topics related to the purchasing intention of the cool helmet.

Numerical Study on the Strength Safety and Displacement Behaviors of a Helmet (헬멧의 강도안전과 변형거동에 관한 수치적 연구)

  • Kim, Chung-Kyun;Kim, Do-Hyun
    • Journal of the Korean Institute of Gas
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    • v.12 no.4
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    • pp.41-45
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    • 2008
  • This paper presents the numerical study on the strength safety and displacement behaviors of a helmet, which is to protect impact forces and to absorb the impact energy. Four different helmet models including a bead frame and a corrugation damper have been analyzed for the stress and the displacement characteristics by using the finite element method. The computed FEM results show that the bead frame on the summit area of the helmet is very useful to increase the strength safety of the helmet, and the corrugation damper on the lower part of the helmet may increase the energy absorption capacity. Thus, this paper recommends the bead frame and the corrugation damper as new design elements of the helmets.

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A Study on the Strength Analysis of the Helmets for Fire and Gas Safety (소방.가스안전용 헬멧의 강도안전성에 관한 연구)

  • Kim, Han-Goo;Shim, Jong-Hyun;Kim, Chung-Kyun
    • Journal of the Korean Institute of Gas
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    • v.12 no.3
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    • pp.31-37
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    • 2008
  • In this paper, the strength analysis has been presented for the stress and strain by using the finite element method for various shell models of the helmets. The advanced helmet that would provide head protection without causing discomfort to the user when it was worn for long periods of time should be manufactured for increasing the safety and workability of the workers. We need a safe, comfortable and light weight of the helmet shell structure. Thus, the helmets had to stand up to the most rigorous conditions encountered for the fire and gas explosion. The FEM computed results show that when the impulsive force is applied on the summit area of a helmet shell structure, the maximum stress and strain have been occurred around the position of an applied impact force, which may lead to the initial failure on the summit of the helmet shell. Thus, the summit area of the helmet shell should be supported by a bead frame and increased thickness of the bead. But the overall thickness of the helmet is to decrease for the light weight of a helmet.

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A Study on the Optimized Design of the Helmets for Fire and Gas Safety (소방.가스안전용 헬멧의 최적설계에 관한 연구)

  • Cho, Seung-Hyun;Kim, Do-Hyun;Kim, Chung-Kyun
    • Journal of the Korean Institute of Gas
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    • v.12 no.3
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    • pp.24-30
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    • 2008
  • In this paper, the stress and strain characteristics of a helmet shell structure have been analyzed by using the finite element method and Taguchi's design method as functions of the material properties, the thickness of a helmet, the thickness and the number of a bead frame. The optimized design of the helmets for a firefighter and a gas worker is very important for increasing the strength safety and an impact energy absorption capacity of a helmet shell due to an impulsive external force. Thus, the optimized design data of the helmet indicated that the uniform thickness of a helmet shell may be reduced for reducing the total weight of a helmet and increasing the strain energy absorption rate, but the thickness and the number of a bead frame would be increased for increasing the impact strength of the helmet.

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A Study for Aging Factor of Bulletproof Helmet : High Temperature Treatment (방탄헬멧의 노화인자에 관한 연구 : 고온 환경 처리를 중심으로)

  • Park, Ho Yun;Gu, Seung Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.6
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    • pp.332-339
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    • 2020
  • This study was a prior study to establish the shelf life of bulletproof helmets, considered the aging factor of bulletproof helmets. To estimate the aging factor of bulletproof helmets, we established a hypothesis that the 'temperature' factor would have the greatest impact on the shelf life of the bulletproof helmet, considering the environmental treatment of the American army's bulletproof helmet's materials. To verify the hypothesis, high temperature acceleration environmental treatment of bulletproof helmets was performed, and the Arrhenius formula was applied to calculate the shelf life. The study result confirmed the negative correlation between bulletproof performance and high temperature, and the influence of temperature as an aging factor was not significant by deriving life by using the Arrhenius model. The limitation of this study is that we couldn't obtain enough samples due to the specificity (miliary supplies) of the test subjects. However, given that the life-related research on bulletproof helmets has not been carried out, this research has great implications and could be used as a reference for improving the Korean Army's bulletproof helmet specifications.

Color Expression in Produce Design applying PCCS Color System -Focusing on Male Bike Helmet Products- (제품디자인에서 PCCS 색체계를 적용한 색채표현 -남성용 자전거 헬멧 제품을 중심으로-)

  • Kim, Young-Seok
    • The Journal of the Korea Contents Association
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    • v.12 no.10
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    • pp.82-92
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    • 2012
  • This study is on the color expression of 100 male bike helmet products examining color image scale with high preference, PCCS color system applied color analysis and influence of color in decision making. The targets are all domestically distributed male bike helmets. The image scale was divided into 4 sections (Soft, Hard, Dynamic and Static) by color, and color image scale was analyzed to top 10 priority products. And analysis according to PCCS color system was made. Finally, questionnaire survey was carried out to analyze the influence of color on purchase decision making. The questionnaire survey was carried out to male in 20s~50s who were the member of 18 bike clubs in S agent in Seoul. 414 out of 422 sheets except for 8 insufficient ones were used. The results can be divided into 3.

Finite Element Analysis on the Displacement Behavior Characteristics of a Safety Helmet with a Corrugation Damper (주름댐퍼를 갖는 안전헬멧의 변형거동특성에 관한 유한요소해석)

  • Kim, Chung-Kyun;Kim, Do-Hyun
    • Journal of the Korean Institute of Gas
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    • v.13 no.4
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    • pp.22-26
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    • 2009
  • In this paper, the displacement behavior and strain energy density characteristics of a safety helmet with various corrugation dampers has been analyzed based on the finite element analysis. The safety helmet is to protect impact forces and to absorb the impact energy. Three different helmet models with a corrugation damper have been compared as functions of the displacement and strain energy density characteristics when the maximum external impulsive force is imposed on the summit of the helmet. The computed FEM results show that the extruded corrugation damper is very useful to increase the damping effect of the helmet. This study indicates that the round corrugation damper may absorb the transferred impact energy successfully. Thus, this paper recommends round and long corrugation damper on the lower part of the helmet as a new design element.

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A Simple Vibration Model for the Imapct Response Analysis of a Helmet (헬멧의 충격응답 분석을 위한 단순진동 모델)

  • Choi, Myung-Jin
    • Journal of the Korean Institute of Gas
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    • v.18 no.1
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    • pp.68-74
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    • 2014
  • In this study, to analyze the impulsive response of a helmet, a simple vibration model is presented. Based upon the experimental data and the simulation results, an equivalent one degree of freedom vibrational system is adapted, and transient impulsive responses are analysed to investigate the influence of engineering parameters such as damping, natural frequency, and impact velocity on the impulsive response of the helmet. Maximum gravitational acceleration reduces as the damping factor value increases. When the damping factor value is around 0.6 or larger, the maximum acceleration does not change. With respect to the natural frequency and the impact velocity, it increases linearly. The relationship between head injury criterion(HIC) and maximum gravitational acceleration is also presented. The scheme of this study is expected to be utilized to economize the design process of high quality helmets.