• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.1
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• pp.33-44
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• 1995

As the occupant safety receives more attention from automobile industries. protection systems have been developed quite well. Developed protection systems must be evaluated through real tests in crash environment Since the real tests are extremely expensive. computer simulations are replaced for some prediction of the real test In the computer simulation. it is very crucial to express the real environment precisely in the modeling precess. The energy absorbing(EA) steering system has a very important rote in vehicle crashes because the occupant can hit the system directly. In this study. the EA steering system is modeled precisely. analyzed for the safely and designed by an optimization technology. First. the EA steering system is disassembled by parts and modeled by segments and joints. The segments are modeled by rigid bodies in motion and they have resistances in contact. Spring-damper elements and force-deflection curves are utilized to represent the joints. The body block test is cal lied out to validate. the modeling. When the test results are not enough for the detailed modeling. the differences between tests and simulations are minimized to calculate unknown parameters using optimization. The established model is applied to a crash simulation of a full-car model and tuned again. After the modeling is finished. components of the steering system are designed by an optimization algorithm. In the optimization process. the compound injury of a driver is defined and minimized to determine the chracteristics of the components. The second. order approximation algorithm has been adopted for the optimization.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.8
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• pp.799-806
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• 2009

Thoracic injury from restraint loading is the principle causative factor of death, which was shown to be particularly significant for older drivers. To characterize thoracic response to belt loading of older drivers, detailed finite element models of the adult and aged thorax were developed. The geometry of the 50th percentile adult male was chosen for the adult FE model. The thoracic FE model was validated against data obtained from results of PMHS pendulum impact tests. The quantified patterns of age-related shape and well-established material changes were applied to the adult model to develop the aged model. Belt force and chest deflection were applied to the developed two types of models. Rib and clavicle fracture risk obviously increased in the aged model. This finding showed that larger rib angle and reduced material properties of the ribcage produced more higher risk of injury in the older driver.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.5
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• pp.136-144
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• 2013

An extensive real world in-depth crash accident data is needed to make a precise occupant injury risk prediction at crash accidents which might be a critical information from the scene of the accident in ACNS(Automatic Crash Notification System). However it is rather unfortunate that there is no such a domestic database unlike other leading countries. Therefore we propose a numerical method, i.e., crash simulation using a sled model to make a virtual database that can substitute car crash database in real world. The proposing crash injury risk prediction is validated against a limited domestic crash accident data.

• International Journal of Automotive Technology
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• v.6 no.2
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• pp.161-169
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• 2005

Neck injuries sustained during low speed rear impact are the most commonly sustained traffic injury. Therefore, the analysis of neck injury mechanisms and methods for mitigating and reducing neck injuries during low speed rear impact are a very important issue in the vehicle safety field. In order to find a method to absorb the shock that is transmitted to the occupant, the response of frontal and rear dummy due to the motion of the struck vehicle and the rotational angular displacements of dummies' necks during rear impact at 12km/h speed were investigated using a Working Model 2D. The results suggest that the shock absorption system should be equipped in the bottom of the seat of the vehicle to reduce shock and mitigate neck injury to the occupants.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.6
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• pp.144-155
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• 1999

An occupant analysis code SAFE (Safety Analysis For occupant crash Environment) is utilized to simulate and improve the crash performance of an energy absorbing steering system. The safety standard FMVSS 203 is simulated and used for design evaluations . Segments and contact elliposids are utilized to model the bod blocks and the components of the steering system with SAFE. Spring-damper elements and force-deflection characteristics are utilized to model the energy absorbing components such as the plate and the polyacetal molding. The plate absorbs the impact energy through tensile deformation . Whereas, the polyacetal molding absorbs the impact energy through compression. the body block test is carried out to validate tie simulation model, and real component tests are performed to extract the force-deflection curves . After the model is validated , the parameter study is carried out to evaluate the crash performance of the energy absorbing components. A performance measure is defined for the parameter study. Using the results of the parameter study and managing the orthogonal arrays, optimum design values of energy absorbing components are determined to minize the occupant injury.

• Journal of Auto-vehicle Safety Association
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• v.15 no.3
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• pp.59-65
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• 2023

As advanced driving assistance system (ADAS) and autonomous driving performance continue to improve, existing crash accidents and crash types are changing. Accordingly, the collision angle and the seating posture of the occupant are changed. It is necessary to study how the occupant injury mechanism changes according to these different crash types. In this regard, a representative crash test mode was derived when the automatic emergency braking system (AEB), one of the autonomous driving performance, was applied to the representative car-to-car crash scenario in Korea. The derived crash test mode was used to analyse the mechanisms of collision injuries according to both impact angle and the occupant seating posture (reclined seat-back angle). The results obtained through this study can be utilized as reference data for the development of new crash evaluation methods and improvements in crash restraint systems for enhancing crash safety.

• Structural Engineering and Mechanics
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• v.18 no.3
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• pp.287-301
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• 2004

Structural acceleration regulation is a means of managing structural response energy and enhancing the performance of civil structures undergoing large seismic events. A quadratic output regulator that minimizes a measure including the total structural acceleration energy is developed and tested on a realistic non-linear, semi-active structural control case study. Suites of large scaled earthquakes are used to statistically quantify the impact of this type of control in terms of changes in the statistical distribution of controlled structural response. This approach includes the impulses due to control inputs and is shown to be more effective than a typical displacement focused control approach, by providing equivalent or better performance in terms of displacement and hysteretic energy reductions, while also significantly reducing peak story accelerations and the associated damage and occupant injury. For earthquake engineers faced with the dilemma of balancing displacement and acceleration demands this control approach can significantly reduce that concern, reducing structural damage and improving occupant safety.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.686-693
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• 2003

An intensive study was conducted for crashworthiness structural design of recently developed Korean High Speed Train. Two nam design concepts are setup to protect the both crews and passengers from serious injury at heavy collision accidents, and to reduce damages of the train itself at light collision accidents. For occupant protection a collision against a movable 15 tons rigid obstacle at 110 kph and a train-to-train collision at 30 kph were selected as accident scenarios for the heavy collisions based on the train accident investigations. A train-to-train collision at 8 kph was used for the light collisions. The crashworthiness behaviors of KHST have been evaluated numerically using the finite element method. Also, one-dimensional collision analyses show good crashworthy responses in a full rake consist and 3-dimensional shell element analyses do in the front-end structures of the power car. Occupant analyses and sled tests demonstrated that KHST performs well enough to protect occupants under the considered accident scenarios.

• Journal of Auto-vehicle Safety Association
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• v.14 no.4
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• pp.100-105
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• 2022

Oblique car to car frontal impact is quite common on the road and series of studies have been done to realize this in the lab. At a certain angle of oblique crash a car (ego) is to travel at a speed of xkm/h to hit the other car(traffic) which is approaching to ego at a speed of ykm/h. Symmetry of the speed of two vehicles, x vs. y, is studied with respect to the impulse of the ego vehicle as well as occupant injury. If there is symmetry of speed of two vehicles, number of case studies needed to analyze the oblique frontal impact may decrease: ex. in the case of 30degree oblique crash 40km/h (ego) / 80km/h (traffic) will show the similar behavior as 80km/h (ego) / 40km/h (traffic) crash.

• Journal of Auto-vehicle Safety Association
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• v.16 no.2
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• pp.34-43
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• 2024

As the autonomous vehicle is to come to the commercial market, passive safety of the vehicles becomes ever more important, since more responsibility of the car crash accidents will be imposed on the car makers. To cope with such a requirements, comprehensive studies are under progress in car OEM's as well as relevant institutes. In this study FE models of two identical family sedans are utilized to investigate the effect of crash parameters like crash impact locations, and impact angle. Relationship between structural behavior of the car and the dummy injury measures is studied.