• 오토저널
• /
• 제15권3호
• /
• pp.111-119
• /
• 1993

In this study, the transient impact structural stress analysis of tracked vehicle structures under recoil impact load is investigated. ANSYS, ABAQUS Code are used for modelling and analytical procedures. The highest maximum Tresca stress occurs on race ring portion and its stress level is (.sigma.$_{T}$)$_{max}$ =20-40kgf/m $m^{2}$. The second highest stress occurs on upper plate of chassis and down plate of turret. The maximum stress level increases with loading direction and elevation angle. The results from liner static load analysis are very much different with impact analysis. Therefore, the practical solutions of structures under impact load can be obtained by only nonlinear transient impact analysis. The impact stress analysis of the steel vehicle structures is conducted. The maximum stress level is less than (.sigma.$_T/)$_{max}$m $m^{2}$. So, the design concept of steel structures can be adapted for new alternatives.s.s.s..s.

• 한국자동차공학회논문집
• /
• 제25권3호
• /
• pp.374-379
• /
• 2017

In vehicle to pedestrian accidents, cracks occur in the vehicle laminated glass due to impact of a pedestrian's head. In this study, FMH(Free Motion Headform) was used to experiment on and analyze the crack patterns on a vehicle laminated glass that collides with an adult headform at speeds of 20 km/h, 30 km/h, and 40 km/h, respectively. Applying the acquired experimental data and material property of the vehicle laminated glass to the structural analysis program LS-Dyna, we could develop the FE model of vehicle laminated glass similar to real vehicle laminated glass. We could estimate the head impact velocity and pedestrian's vehicle impact velocity using the Madymo program.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2002년도 춘계학술대회 논문집
• /
• pp.353-356
• /
• 2002

In vehicle accidents, the rolling, pitching, and yawing which are produced by collisions affect the motions of vehicle. Therefore, vehicle behavior under impact situation should be analyzed in three-dimension. In this study, three-dimensional vehicle dynamic equations based on impulse-momentum conservation principles under vehicle impact are introduced for simulation. This analysis has been performed by the real vehicle impact data from JARI and RICSAC. This study suggested each system modeling such as suspension, steering, brake and tire as well as the appropriate vehicle behavior simulation model with respect to pre and post impact.

• 자동차안전학회지
• /
• 제14권4호
• /
• pp.77-83
• /
• 2022

Occupant behaviors and body contact with vehicle interior parts are main injury mechanism in far-side collisions. In vehicle side impact accident where the crash accident occurs on the opposite side of the vehicle from the a particular occupant, it is exposed in terms of relatively larger lateral motion to interact with the opposite side of the vehicle structure. The challenge of minimizing motions of upper body and injury risk according to a direct contact is a primary occupant protection research. This study has performed a data analysis of real-world accident database extracted from the 2016~2020 CISS database and a parametric investigation of impact angles and occupant kinematics in far-side lateral and oblique impact simulations. A detailed data analysis was conducted to reveal the relationship among the accident and injury data. Database analysis and computational far-side impact results proposed the fundamental vehicle design for safety improvement in far-side collisions.

• 한국정밀공학회지
• /
• 제23권12호
• /
• pp.88-94
• /
• 2006

In this study, the dynamic impact analysis for the passenger air-bag(PAB) module has been carried out by using FEM to predict the dynamic characteristics of vehicle ride safety against head impact. The impact performance of vehicle air-bag is directly related to the design parameters of passenger air-bag module assembly, such as the tie bar bracket's width and thickness, respectively, However, the product's design of PAB module parameters are estimated through experimental trial and error according to the designer's experience, generally. Therefore, the dynamic analysis of head impact test of the passenger air-bag module assembly of automobile is needed to construct the analytical methodology At first, the FE models, which are consist of instrument panel, PAB Module, and head part, are combined to the whole module system. Then, impact analysis is carried out by the explicit solution procedure with assembled FE model. And the dynamic characteristics of the head impact are observed to prove the effectiveness of the proposed method by comparing with the experimental results. The better optimized impact performance characteristics is proposed by changing the tie bracket's width md thickness of module. The proposed approach of impact analysis will provides an efficient vehicle to improve the design quality and reduce the design period and cost. The results reported herein will provide a better understanding of the vehicle dynamic characteristics against head impact.

• 대한토목학회논문집
• /
• 제30권6D호
• /
• pp.605-613
• /
• 2010

본 연구에서는 소형차도로 방호울타리 형식선정의 필수요소인 충돌계수 분석 및 방호울타리 높이 선정을 위해 현재의 기준을 적용하는 과정에서 생긴 문제점을 파악하여 개선점을 제시하고 이를 해외기준과 비교분석하여 방호울타리의 형식결정을 위한 기준을 제시하였다. 이를 위해 소형차관련 사고사례분석을 실시하였고, 사고사례를 토대로 방호울타리의 형식선정에 중요인자인 충돌각도, 충돌차량, 충돌속도를 비교 분석 및 소형차 방호울타리의 소요높이를 결정하였다. 충돌각도의 경우 편도 2차로 고속도로 사고사례를 분석하여 유럽 RISER 연구 결과와 비교하여 상향조정의 필요성을 도출하였다. 충돌차량의 경우 경차, 소형승용차, 중형 및 대형승용차, 승용차(SUV), 승합차 및 소형 트럭으로 나누어 분석을 실시하였으며, 충돌사고소형차 사고누적율에 기반한 차량중량 및 충돌속도를 회귀분석하였으며 수도권고속도로 누적통행비율을 감안 충돌중량을 결정하였다. 또한 그 결과를 토대로 소형차도로 방호울타리 높이를 계산하였다. 본 연구의 결과는 향후 소형차도로 형식선정에 중요한 인자가 된다.

• 한국소음진동공학회논문집
• /
• 제16권7호
• /
• pp.754-761
• /
• 2006

This paper presents the dynamic characteristics of MR impact damper for vehicle collision system. Various types of mechanism have been proposed to reduce force transmitted to the vehicle chassis and finally to protect occupants from injury. In the case of head-on collision, the bumper makes main role of isolation material for collision attenuation. In this study, the proposed bumper system consists of MR impact damper and structures. The MR impact damper utilizes MR fluid which has reversible properties with applied magnetic field. The MR fluid operates under flow mode. The bellows is used for generation of fluid flow. A mathematical model of the MR impact damper is derived incorporating with Bingham model of the MR fluid. Field dependent damping force is investigated with time and frequency domain. The MR impact damper is then incorporated with vehicle crash system. The governing equation of motion of vehicle model is formulated considering occupant model. Dynamic characteristics of vehicle collision system investigated with computer simulation.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2006년도 춘계학술대회논문집
• /
• pp.147-152
• /
• 2006

This paper presents the dynamic characteristics of MR impact damper for vehicle collision system. Various types of mechanism have been proposed for reduce transmitted force to vehicle chassis and finally protect occupants from injury. In the case of frontal collision, the bumper make main role of isolation material for collision attenuation. In this study, proposed bumper system composed of MR impact damper and structures. The MR impact damper is to adopted MR fluid which has reversible properties with applied magnetic field. MR fluid operates under flow mode with Bingham flow and bellows is used for generation of fluid flow. Mathematical model of MR impact damper incorporated with MR fluid is established. Field dependent damping force is investigated with time and frequency domain. The MR impact damper is then incorporated with vehicle crash system. The governing equation of motion of vehicle model is formulated considering occupant model. Dynamic characteristics of vehicle collision system investigated with computer simulation.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2012년도 추계학술대회 논문집
• /
• pp.613-616
• /
• 2012

A multi body simulation (MBS) model is developed for predicting the impact harshness of the vehicle. Impact harshness is the vehicle performance to evaluate the impulsive vibration behavior during driving over an obstacle of the road. Thus, the approach is simulated on the time domain for considering the transient behavior of the vehicle. The validity of vehicle component modeling of bushes, dampers and structure flexibilities is verified. The simulations are compared with the test results in both of vertical and longitudinal directions. In particular, the vertical vibration of the vehicle is significantly affected by the body flexibility. Through the sensitivity analysis, main factors for the impact harshness performance are investigated.

• 한국강구조학회 논문집
• /
• 제23권2호
• /
• pp.199-210
• /
• 2011

사장교의 케이블은 타 부재에 비해 단면적이 매우 작고 고응력 상태이므로 진동에 매우 민감한 부재이다. 따라서 사장교 케이블의 충격계수는 실제 차량의 주행으로 발생하는 동적 효과를 반영하여 평가하는 것이 합리적이다. 이에 본 연구에서는 차량 중량, 케이블 모델, 노면조도, 차량속도 및 차량간격의 설계변수를 고려하여 중앙경간 230m 및 540m의 강합성 사장교를 대상으로 차량 이동하중 해석을 수행하여 케이블의 충격계수를 평가하고, 현재 실무에서 사용되고 있는 영향선을 이용한 방법과 비교하였다. 본 연구에 사용된 노면조도는 ISO 8608 규정에 근거하여 랜덤 생성하였으며, 생성 회수에 따른 케이블 충격계수의 수렴 추이를 분석함으로써 결과의 신뢰도를 확보하였다. 또한, 차량모델은 9-자유도를 갖는 트랙터-트레일러 형식의 트럭 모델을 적용하였으며 차량의 운동방정식은 Lagrange운동방정식으로부터 유도하였다. 해석 대상 교량은 3차원 유한요소모델로 구축하였으며 보강형과 주탑은 보요소, 케이블은 등가탄성계수를 갖는 트러스요소를 사용하였다. 이동하중으로 인한 교량-차량 상호작용 해석에는 직접적분법을 사용하였으며, 교량의 변위 오차율이 허용 범위 내에 수렴될 때까지 반복 해석을 수행하였다. 그 결과, 실제 차량의 주행으로 발생하는 동적 효과를 고려하지 못하는 영향선 기법은 차량 이동하중 해석에 비해 측경간 단부 케이블의 충격계수를 과소평가할 수 있는 것으로 나타났다.