• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.4
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• pp.142-151
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• 1997

In order to reduce passenger injuries in side collisions, car makers are developing a side impact airbag system while Volvo has already adopted. This study examines dummy injury reduction effect of a side airbag system using full car side impact simulation according to FMVSS 214 test procedure. The simulation result without side airbag shows a good correlation with test data. The folded airbag simulation is carried out to check main design factors. Through the simulation with side airbag module integrated in the seat frame, it is found that the side airbag system provides a substantially enhanced protection for car occupants in side collisions.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.6
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• pp.236-246
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• 1996

The deployment process of fully folded airbag is analyzed. The methodology of finite element modeling is presented for flat driver side airbag and 3-dimensional passenger side airbag. 'Initial metric option' is used to model 3-dimensional passenger side airbag before deployment. The deformed shapeds and pressure waveforms inside cushion evaluated from simulation are compared to the test results. The agreements between the simulation and the experiments are satisfactory, and the results of simulation are confirmed to be applied to the design of airbag module.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.10
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• pp.1189-1195
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• 2011

For side airbag, the pipe type inflators have been wide used while the disk type inflators have been used for front airbag. For helping to prevent injury and death the airbag inflator system should be design with great care. The present study deal with optimizing the design of side airbag inflator by finite element analysis and design of experiment method. An optimization process was integrated to determine the optimum design variable values related to the side airbag inflator. Free shape optimization method has been carried out to find a optimal shape on an side airbag inflator model. Optimization of the air bag inflator was successfully developed using Sharpe optimization was carried out to find a new geometry. The improved results compared to the base design specification were achieved from design of experiment and optimization.

• Journal of Auto-vehicle Safety Association
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• v.10 no.3
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• pp.7-12
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• 2018

The Korean New Car Assessment Program (KNCAP) is a program to evaluate the safety of automobiles. In the safety assessment method, there are frontal collision, partial frontal collision, side collision, pillar collision, and left stability in the collision safety category. Among them, Korean in-depth analysis data shows that there are a lot of side collision accidents and it is necessary to protect them. This study will analyze the side collision accident that occurred in actual traffic accident based on Korea In-Depth Accident Study (KIDAS) and investigate the effect of center airbag on passenger in under side collision. In addition, with simulated side collision scenarios in the various side impact directions, it was investigated how the center airbag affects the driver and passenger in terms of kinematic and injury levels.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.5
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• pp.45-54
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• 1998

For proper release of side airbags, the onset of crash should be detected first. After crash detection, the algorithm has to make a decision whether the side airbag deployment is necessary. If the deployment is necessary, proper timing has to be provided for the maximum protection of driver or passenger. The side airbag release algorithm should be robust against the statistical deviations which are inherent to experimental crash test data. Deterministic optimization algorithms cannot be used for the side aribag release algorithm since the objective function cannot be expressed in a closed form. From this background, genetic algorithm has been used for the optimization. The optimization requires moderate amount of computation and gives satisfactory results.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.4
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• pp.220-225
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• 2000

This paper develops a finite element model for studying occupant behavior of a mid-size truck equipped with a driver side airbag. The developed model simulates an occupant behavior using PAM-CRASH/PAM-SAFE in super computer SP2. The model is developed based on a sled test. A 50% hybrid dummy III is used for measuring head and chest accelerations and femur loads, and major injury coefficients such as HIC, CA and femur load. Inferior components such as foot rest, seat, kneebolster, crash pad, etc. are roughly modeled and defined by a rigid material model. And contact type II is used for detecting a contact with dummy. Contact type II definition uses force-deflection relationship of each body Such components as steering column which directly affect on the occupant injuy are modeled in detail and defined by an elastic-plastic material model. Airbag cushion is modeled using rivet elements. Airbag cover groove is modeled using rivet elements. Airbag tether is modeled as nonlinear bar elements. Airbag model has two vent holes to ventilating the exploded gas. Airbag is folded close to the real airbag folding procedure, and folded cautiously in order not to have initial penetration. A vehicle pulse acquired from 31mph frontal barrier test is used as input signal for the simulation. The simulation conditions are tuned to the sled test ones. The measured dummy accelerations and major injury coefficients, and filmed dummy behavior and airbag inflation process using high speed camera are compared to the simulation results to verify the developed finite element model.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.1
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• pp.129-135
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• 2013

There is not enough absorption space in the side of a vehicle so injuries to a passenger are higher compared to frontal impact injuries. For the protection of the passenger in the event of a side impact, vehicle regulations and new car assessment program(NCAP) are implemented all over the world. However, passive safety such as absorption technology of vehicle body itself is limited due to the narrow space of the side part. At the present time, it is well known that a side airbag including a curtain airbag is the most effective system to protect the passenger during a side impact. In this study, optimum design of the curtain airbag is carried out to reduce Head Injury Criterion(HIC) of the passenger. Based on crashworthiness simulation, an orthogonal array is selected based on the defined design variables, the response surfaces are generated from the orthogonal array and optimization is conducted with the surfaces.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.2
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• pp.104-113
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• 2013

New USNCAP has been carried out by NHTSA including front and side crash from MY2011. In this paper, test results for USNCAP Side crash were reviewed by statistical analysis. This review focused on side crash test results to investigate the effect of changes from new USNCAP side crash test protocol among 30 passenger cars. These results were summarized as followings. Total number of 5 star vehicles on the front seat dummy (16 vehicles, 53.3%) was slightly smaller than the rear seat's (17 vehicles, 56.7%) in MDB test. For the ES-2re dummy, chest injury, ie maximum rib deflection contributed to 66% in the mean value of $P_{joint}$. Pelvis injury was highly dependent upon performance up to 87% in the SID-IIs dummy cited on the rear seat in average $P_{joint}$. For Pole test, pelvis injury made contribution to the average performance to 83%. For standard deviation, it showed the largest value in the same body region as the mean value for each dummy. Overall front seat performance showed 14 vehicles, 44.6% with 5 star vehicles less than each MDB or Pole test result. This result showed that performances in MDB test were different pattern to Pole test on driver position. Number of 5star vehicles for overall side NCAP performance are 18 passenger cars (60%). Curtain airbag and driver thorax airbag were equipped in all test vehicles. One vehicle is equipped with thorax airbag in the rear seat. Results from two side tests considered as reliability problem, ie the cause for large standard deviation in side crash test. Consequently, the countermeasure for new USNCAP side crash test is essential to design the effective side structures for side collision and to control well dummy kinematics with curtain and thorax airbag in order to reduce chest and pelvis injuries.

• Journal of Auto-vehicle Safety Association
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• v.13 no.3
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• pp.60-68
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• 2021

Invisible passenger airbag door system of hard panel types must be designed with a weakened area such that the side airbag will deploy through the instrument panel as like intended manner, with no flying debris at any required operating temperature. At the same time, there must be no cracking or sharp edges in the head impact test. If the advanced airbag with the big difference between high and low deployment pressure ranges are applied to hard panel types of invisible passenger airbag (IPAB) door system, it becomes more difficult to optimize the tearseam strength for satisfying deployment and head impact performance simultaneously. It was introduced the 'Operating Window' idea from quality engineering to design the hard panel types of IPAB door system applied to the advanced airbag for optimal deployment and head impact performance. Zigzab airbag folding and 'n' type PAB mounting bracket were selected.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.3
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• pp.163-170
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• 2000

Accident statistics shows that the portion of fatal occupant injuries due to side impacts is considerably high. The side impact usually leads to a severe intrusion of side structure into the passenger compartment. Furthermore, the safety zone for the side impact is relatively small compared to the front impact. Those kinds of physics for side impact frequently result in a fatal injury for the occupant. Therefore, NHTSA and EEVC are trying to intensify the regulation for the occupant protection against side impact. Both the regulation and recent market trends are asking for an installation of side airbag. There are several types of system configuration for side impact sensing. In this paper, we adopt the acceleration-based remote sensing method for the side airbag control system. We mainly focus on the development of hardware and crash discrimination algorithm of remote sensing unit. The crash discrimination algorithm needs fast decision of airbag firing especially for high-speed side impact such as FMVSS 214 and EEVC tests. It is also required to distinguish between low-speed fire and no-fire events. The algorithm should have a sufficient safety margin against any misuse situation such as hammer blow, door slam, etc. This paper introduces several firing criteria such as acceleration. velocity and energy criteria that use physical value proportional to crash severity. We have made a simulation program by using Matlab/Simulink to implement the proposed algorithm. We have conducted an algorithm calibration by using real crash data for 2,500cc vehicle. The crash performance obtained by the simulation was verified through a pulse injection method. It turned out that the results satisfied the system requirements well.