• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.407-408
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• 2006

Passenger safety is one of the most important considerations in the purchase of an automobile. A curtain-type air bag is increasingly adapted in deluxe cars for protecting passengers from the danger of side clash. Inflator housing is a main part of the curtain-type air bag system for supplying high-pressure gases to pump up the air bag-curtain. Although the inflator housing is fundamental in designing a curtain-type air bag system, flow information on the inflator housing is very limited. In this study, we measured instantaneous velocity fields of a high-speed flow ejecting from the inflator housing using a dynamic PIV system. From the velocity field data measured at a high frame-rate, we evaluated the variation of the mass flow rate with time. From the instantaneous velocity fields of flow ejecting from the airbag inflator housing in the initial stage, we can see a flow pattern of broken shock wave front and its downward propagation. The flow ejecting from the inflator housing was found to have large velocity fluctuations and the maximum velocity was about 700m/s. The velocity of high-speed flow was decreased rapidly and the duration of high-speed flow over 400m/s was maintained only to 30ms. After 100ms, there was no perceptible flow.

• Journal of Sensor Science and Technology
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• v.18 no.5
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• pp.385-392
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• 2009

This paper describes the algorithm development of a new body pressure detection sensor for occupant classification system. U.S. Government has required that advanced airbag system should be installed to every automobiles after 2006 according to FMVSS 208 regulation. Therefore, Occupant Classification System should be provided the passenger with safety in order to protect the infants or children that sit in the front passenger seat. When an occupant sits on the chair of the vehicle, deployment of the airbag depends on passenger's weigh distribution and postures. Authors have been developed a new pattern recognition of passenger and weight distribution at the same time by Force Sensing Resistor for the safety.

• Journal of Auto-vehicle Safety Association
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• v.13 no.4
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• pp.66-72
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• 2021

This study was initiated to improve of the defect investigation method using event data recorders (EDR) and suggested a solution through the regulation and system analysis of EDR. The EDR data has been used for various purposes such as the vehicle defect investigation and the traffic accident investigation. However the EDR regulation has not been updated since the implementation in 2012. "Trigger Threshold" can be used to analyze a single accident such as the frontal crash, the side crash, and the rollover. In the case of a complex accident in which a rollover accident and a crash accident occur simultaneously, it is difficult to analyze a complex accident due to current "Trigger Threshold". This study proposed the method of separating the "Trigger Threshold" into a crash accident and a rollover accident so that accidents can be analyzed using the EDR data even when a complex accident occurs. In addition, it proposed the improvement method to quickly use the data of EDR in accident reconstruction software.

• Computers and Concrete
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• v.29 no.4
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• pp.209-217
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• 2022

In order to analyze the static and dynamic structural characteristics of the Obermeyer gate under overflow conditions, the force characteristics and vibration characteristics of the shield plate structure are studied based on the fluid-solid coupling theory. In this paper, the effects of the flow rate, airbag pressure and overflow water level on the structural performance of shield plate of air shield dam are explored through the method of controlling variables. The results show that the maximum equivalent stress and total deformation of the shield plate decrease first and then increase with the flow velocity. In addition, they are positively correlated with the airbag pressure. What's more, we find that the maximum equivalent stress of the shield plate decreases first and then increases with the overflow water level, and the total deformation of the shield plate decreases with the overflow water level. What's more importantly, the natural frequency of the shield structure of the Obermeyer gate is concentrated at 50 Hz and 100 Hz, so there is still the possibility of resonance. Once the resonance occurs, the free edge of the shield vibrates back and forth. This work may provide a theoretical reference for the safe and stable operation of the shield of the Obermeyer gate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.597-602
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• 2021

Even in the era of the 4th industrial revolution, the prevention of industrial accidents is still an important issue in industrial sites. In solving the problem of industrial safety, a product can be difficult to market if there is a lack of standard or method for a reliable performance evaluation. The purpose of this study was to develop and evaluate a test method for a wearable airbag product for protecting the body from falls that was newly developed to respond to fall accidents in industrial sites. As a research method, reliable evaluation standards were developed and applied through four stages of the evaluation and development process (Step 1: Product review, Step 2: Data research, Step 3: Expert meeting, Step 4: Drawing evaluation standard). In addition, the impact force was evaluated according to the developed evaluation standard. The fall impact force obtained through the evaluation showed a reduction effect of approximately 96% compared to the existing impact force. Therefore, the fall impact force was reduced significantly when the airbag was applied. This will enable new convergence products to be launched on the market and produce an environment where industrial workers can work safely.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.2
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• pp.408-413
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• 1996

A self-diagnostic, air-damped, piezoresitive, cantilever-beam microaccelerometer has been designed, fabricated and tested for applications to automotive electronic airbag systems. A skew-symmetric proof-mass has been designed for self-diagnostic capability and zero transverse sensitivity. Two kinds of multi-step anisotropic etching processes are developed for beam thickness control and fillet-rounding formation, UV-curing paste has been used for sillicon-to-glass bounding. The resonant frequency of 2.07kHz has been measured from the fabricated devices. The sensitivity of 195 $\mu{V}$/g is obtained with a nonlinearity of 4% over $\pm$50g ranges. Flat amplitude response and frequency-proportional phase response have been obserbed, It is shown that the design and fabricaiton methods developed in the present study yield a simple, practical and effective mean for improving the performance, reliability as well as the reproducibility of the accelerometers.

• International Journal of Automotive Technology
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• v.7 no.5
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• pp.571-577
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• 2006

This paper deals with dynamic tensile characteristics for the polypropylene used in an IP(Instrument Panel). The polypropylene is adopted in the dash board of a car, especially PAB(Passenger Air Bag) module. Its dynamic tensile characteristics are important because the PAB module undergoes high speed deformation during the airbag expansion. Since the operating temperature of a car varies from $-40^{\circ}C$ to $90^{\circ}C$ according to the specification, the dynamic tensile tests are performed at a low temperature($-30^{\circ}C$), the room temperature($21^{\circ}C$) and a high temperature($85^{\circ}C$). The tensile tests are carried out at strain rates of six intervals ranged from 0.001/sec to 100/sec in order to obtain the strain rate sensitivity. The flow stress decreases at the high temperature while the strain rate sensitivity increases. Tensile tests of polymers are rather tricky since polymer does not elongate uniformly right after the onset of yielding unlike the conventional steel. A new method is suggested to obtain the stress-strain curve accurately. A true stress-strain curve was estimated from modification of the nominal stress-strain curves obtained from the experiment. The modification was carried out with the help of an optimization scheme accompanied with finite element analysis of the tensile test with a special specimen. The optimization method provided excellent true stress-strain curves by enforcing the load response coincident with the experimental result. The material properties obtained from this paper will be useful to simulate the airbag expansion at the normal and harsh operating conditions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.638-643
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• 2019

In order to reduce the cost and weight of the soft-foamed instrument-panel (IP), it was developed the new IP which is made by the two kinds of injection methods. One is the compression-injection with back-foamed foil inserted, and the other is two-shot injection with the passenger airbag door. We named it 'IMX-IP' which means that all components ('X') of the IP with different resins are made in a mold. The development procedure of this technology was introduced (1) Design of the new injection mold through TRIZ method, (2) Optimization of the injection conditions and back foamed-foil for minimizing the foam loss and thickness deviation, (3) Development of CAE for two-shot injection compression, (4) Reliability performance test and application to the mass production. The reduction of the processes through the two-shot injection with back foamed-foil inserted made it possible to enhance soft feeling on IP and reduce the cost and weight simultaneously.

• Journal of Auto-vehicle Safety Association
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• v.3 no.2
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• pp.22-27
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• 2011

The side impact test in the Korean New Car Assessment program (KNCAP) has been conducted since 2003. The side impact test method has been contributed to the improvement of the vehicle side structure and the enhancement of the occupant protection performance for the domestic vehicles. The pole side impact test method introduced in the KNCAP in 2010 to enhance the head protection under the severe side crash environment. The pole side impact test is optional for the additional score to be added to the overall rating score. The test results of side and pole side impact test for five vehicles were introduced and compared.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.9
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• pp.203-211
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• 1999

The research committee for automobile repairs (RCAR), an international body of insurance research centers, has adopted the typical low speed crash test based on an average damage level in crash accidents to estimate the damageability , repairability and safety. The characteristics of body acceleration and the probability of injury are investigated based on damaged components, accelerations of body and injured dummy to analyze damageability and the driver's safety under low speed crash environment. It is found from the experimental results that the probability of head and thorax injuries are very low comparing to the injury criteria of FMVSS No.208. Furthermore, it is suggested that the deployment of airbag may not be necessary at RCAR low speed frontal crash test.