• Journal of the Korean Society for Precision Engineering
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• v.17 no.5
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• pp.195-201
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• 2000

The fundamental spot welded sections of automobiles (hat-shaped and double hat-shaped sections) absorb most of the energy in a front impact collision. The sections of various thickness, shape and weld width on the flange lave been tested on axial impact crush load (Mass 40kg, Velocity 7.19m/sec) using a vertical air pressure crash est device Characteristics of impact collapse have been reviewed and a structure of optimal energy absorbing capacity is suggested.

• Journal of Auto-vehicle Safety Association
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• v.9 no.2
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• pp.33-39
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• 2017

In recent days, crash safety system based on vehicle-to-vehicle communication (V2V) has been legislated. This V2V based safety system collects information from nearby vehicles to predict any crash possibility. Thus, it requires accurate and reliable data. Regularly updated features of Basic Safety Message(BSM) will be used to test validity of various elements included in the BSM. Then, the focus was made on whether values of these elements had notable differences compared to previous values. Through this paper, the validation tool was implemented and the result from V2V OBU experiment was used to identify problems in the current model and additional features that need to be implemented in V2V OBU for more accurate BSM.

• Journal of Auto-vehicle Safety Association
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• v.12 no.1
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• pp.39-45
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• 2020

The express/intercity bus models have been developing for wheelchair users to provide the preferable long-distance travels by the Korean government research. In the previous studies, evaluation method was set up for the wheelchair users' safety and the study for wheelchair occupants' safety was performed under various crash loadings mimic to real accidents, frontal crash, side impact and rollover, etc. This study was focused on the evaluation of occupant behaviors and injuries (head and chest) during vehicle impact loading cases in order to ensure the safety of wheelchair passengers in the bus. The occupant response and belt loading data during the sled FE simulation were compared with those of the sled test. The simulation results showed overall safety tolerances of wheelchair occupants under the severe frontal deceleration, side impact loading based on the FMVSS 214 configuration and bus rollover loading.

• International Journal of Highway Engineering
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• v.15 no.1
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• pp.65-73
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• 2013

PURPOSES: This paper presents the results of computer simulations of roadside safety barrier, called by safety roller guardrail, consisting of rotational roller, rotation control plate, post and subsidiary members. The rotation roller and rotation control plate are made by EVA(ethylene vinyl acetate), and PE(polyester), respectively. METHODS: The occupant risk analysis has been carried out under vehicle crash condition for high containment level of SB-4 for the purpose of local road. Simulations are performed with the finite element code LS/DYNA-3D. RESULTS: The numerical results obtained by LS/DYNA-3D software from the viewpoints of vehicle stability, vehicle trajectory, occupant risk, etc. CONCLUSIONS: It is noted that not only impact severity is drastically reduced but also vehicle trajectory is improved due to the characteristics of energy absorption and rotation pattern of EVA rollers connected by control plates.

• Journal of Mechanical Science and Technology
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• v.14 no.11
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• pp.1232-1243
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• 2000

Motor vehicle accidents in rear impacts cause more than fifty percents of drivers to suffer from neck injuries. It is known that most neck injuries are associated with rear-end collisions at a speed lower than 32 km/h and between the Abbreviated Injury Scale (AIS) 1 and AIS 2. Two different types of low speed crash tests such as the frontal barrier and rear moving barrier crashes have been conducted by following the procedure of the Research Committee for Automobile Repairs (RCAR). The injury for the neck and the Head Injury Criteria (HIC) were measured by using the sensors mounted on dummies. We reviewed neck injures and the relationship between the neck and head injuries, and examined the deceleration of the body. Using the experimental test data at the neck, we investigated an improved neck injury criterion Nij. Also, the effects of the position of a head restraint on reducing the frequency and severity of the neck injury in rear-end collisions were investigated.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.6 s.177
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• pp.1479-1490
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• 2000

The design process of the motor driven tilt/telescopic steering column is established by axiomatic design approach in conceptual design stage. By selecting independent design variables for improvin g performance of the steering system, each detailed design can be carried out independently. In the detailed design, the safety in crash environment and vibration reduction are considered. An occupant analysis code SAFE(Safety Analysis For occupant crash Environment) is utilized to simulate the body block test. Segments, contact ellipsoids and spring-damper elements are used to model the steering column in SAFE. The model is verified by the result of the body block test. After the model is validated, the energy absorbing components are designed using an orthogonal array. Occupant analyses are performed for the cases of the orthogonal array. Final design is determined for the minimum occupant injury. For vibrational analysis, a finite element model of the steering column is defined for the modal analysis. The model is validated by the vibration experiment. Size and shape variables are selected for the optimization process. An optimization is conducted to minimize the weight subjected to various constraints.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.234-241
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• 2002

In this study, the car crash analysis that simulates the crushing behavior of car forestructure during a frontal impact is carried out. The analysis model for front impact of a car consists of the lumped mass and the spring model. The characteristics value of masses and springs is obtained from the static analysis of a target car. The deceleration-time curve obtained from the simulation are compared with NCAP test data from the NHTSA. They show a good agreement with frontal crash test data. The deceleration-time curve of passenger compartment is classified into 3 stages; beginning stage, middle stage, and last stage. And the behavior of masses at each stage is explained. The effect of stiffness variation on deceleration of passenger compartment is resolved. The maximum loaded peak-time of torque box and dash is the main factor to control the passenger compartment's maximum deceleration.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.5
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• pp.201-209
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• 2003

Virtual human models are widely used to save time and expense in vehicle safety studies. A human model is an essential tool to visualize and simulate a vehicle driver in virtual environments. This research is focused on creation and application of a human model fer virtual reality. The Korean anthropometric data published are selected to determine basic human model dimensions. These data are applied to GEBOD, a human body data generation program, which computes the body segment geometry, mass properties, joints locations and mechanical properties. The human model was constituted using MADYMO based on data from GEBOD. Frontal crash and bump passing test were simulated and the driver's motion data calculated were transmitted into the virtual environment. The human model was organized into scene graphs and its motion was visualized by virtual reality techniques including OpenGL Performer. The human model can be controlled by an arm master to test driver's behavior in the virtual environment.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.5
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• pp.29-34
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• 2005

141,841 car-to-car collision had occurred in 2003, and among the accidents 51,796 were rear-end impact. According to insurance company for loss or damage, more than $60\%$ of rear-end impact victims suffer neck injury. This means at least 31,000 neck injury victims have happened in 2003. More than $97\%$ of the neck injury victims have low severity injury than A.I.S 2. Head restraint, which is designed to limit rearward head movement and equipped on seat, can considerably protect neck from rear-end impact. In this paper we evaluated head restraint geometry and drivers' sitting position according to RCAR standard and carried out low speed volunteer crash test. The crash speed is 4km/h and N.I.C value is used to determine injury probability. Through these research results we can introduce the method to prevent neck injury at rear-end impact.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.04b
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• pp.150-155
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• 2000

In this study, deformation analysis for solid-liquid coupled structure has been performed using explicit finite element program In order to model the behavior of liquid, SPH (Smooth Particle Hydrodynamics) algorithm was adopted. Crash test and simulation for the hydro-type impact energy absorber were given as an example of industrial application. The obtained good correlation between the test results and simulation reveals that the proposed method could be used effectively for the structural analysis of solid-liquid coupled problems