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Technical Paper

A New Approach to Occupant Simulation Through the Coupling of PC-Crash and MADYMO

1999-03-01
1999-01-0444
During recent years the accident simulation program PC-Crash was developed. This software simulates vehicle movement before, during and after the impact, using 3D vehicle and scene models. ...A new interface has been developed between MADYMO® and PC-Crash so that, after the reconstruction of an accident, only a few additional parameters regarding restraint system, seat and occupant must be defined. ...A new interface has been developed between MADYMO® and PC-Crash so that, after the reconstruction of an accident, only a few additional parameters regarding restraint system, seat and occupant must be defined. PC-Crash then creates all necessary input files for MADYMO® and starts the occupant simulation.
Technical Paper

Effective Numerical Simulation Tool for Real-World Rollover Accidents by Combining PC-Crash and FEA

2007-04-16
2007-01-1773
In this work, we focused on the trip-over type, which occurs most frequently, and performed simulations to reproduce real-world rollover accidents by combining PC-Crash and FEA. At first, using a simplified full car model, sufficient conditions, such as additional velocity, required for a curb trip-over accident to occur, were derived from energy balance concept based on the same principle as critical sliding velocity (CSV) criterion. ...Based on rigid body dynamics, PC-Crash software was chosen to make an accident reconstruction analysis of some selected cases chosen from an accident database (NASS-CDS). ...The output of this PC-crash simulation was then used as the initial input conditions (i.e., speed, deceleration, etc.) of a detailed finite element analysis.
Technical Paper

Application of the Monte Carlo Methods for Stability Analysis within the Accident Reconstruction Software PC-CRASH

2003-03-03
2003-01-0488
During recent years the accident simulation program PC-CRASH was developed, which allows simulating the vehicles movement before, during and after the impact. ...The first one serves as an alternative for the optimizer tool and is included in the current version of PC-Crash. It gives reasonable insight in the variation of certain parameters in reasonable calculation time.
Technical Paper

Soil Trip Rollover Simulation and Occupant Kinematics in Real World Accident

2007-08-05
2007-01-3680
In this work, we focused on the trip-over type, which occurs most frequently, and performed simulations to reproduce real-world rollover accidents by combining PC-Crash and FEA. Soil trip-over simulation was carried out based on real world accidents. Based on rigid body dynamics, PC-Crash software was chosen to make an accident reconstruction analysis of some selected cases chosen from an accident database (NASS-CDS). ...Based on rigid body dynamics, PC-Crash software was chosen to make an accident reconstruction analysis of some selected cases chosen from an accident database (NASS-CDS). ...The output of this PC-crash simulation was then used as the initial input conditions (i.e., speed, deceleration, etc.) of a detailed finite element analysis.
Technical Paper

Field Effectiveness Calculation of Integrated Safety Systems

2011-04-12
2011-01-1101
The vehicle dynamics of all scenarios from the database will be simulated in PC-Crash, an accident-reconstruction software. Since the brake assist is obligatory from 2012 on, the system and its effect on each single accident scenario will be modeled.
Technical Paper

Simulation and Testing of a Suite of Field Relevant Rollovers

2004-03-08
2004-01-0335
Automotive rollover is a complex mechanical phenomenon. In order to understand the mechanism of rollover and develop any potential countermeasures for occupant protection, efficient and repeatable laboratory tests are necessary. However, these tests are not well understood and are still an active area of research interest. It is not always easy or intuitive to estimate the necessary initial and boundary conditions for such tests to assure repeatability. This task can be even more challenging when rollover is a second or third event (e.g. frontal impact followed by a rollover). In addition, often vehicle and occupant kinematics need to be estimated a-priori, first for the safe operation of the crew and equipment safety, and second for capturing and recording the event. It is important to achieve the required vehicle kinematics in an efficient manner and thus reduce repetitive tests. Mathematical modeling of the phenomenon can greatly assist in understanding such kinematics.
Technical Paper

Development of CAE Methodology for Rollover Sensing Algorithm

2009-04-20
2009-01-0828
The Rollover CAE model is developed for Rollover sensing algorithm in this paper. By using suggested CAE model, it is possible to make sensing data of rollover test matrix and these data can be used for calibration of rollover sensing algorithm. Developed vehicle model consists of three parts: a vehicle parts, an occupant parts and a ground boundary conditions. The vehicle parts include detailed suspension model and FE structure model. The occupant parts include ATD (anthropomorphic test device) male dummy and restraint systems: Curtain Airbag and Seat-Belt. We find analytical value of the suspension model through correlation with vehicle drop test, simulate this model under the conditions of untripped (Embankment, Corkscrew) and tripped (Curb-Trip, Soil-Trip) rollover scenarios. Comparison of the simulation and experimental data shows that the simulation results of suggested CAE model can be substituted for the experimental ones in calibration of rollover sensing algorithm.
Standard

Rollover Testing Methods

2017-07-28
CURRENT
J2926_201707
The scope of this document is to provide an overview of the techniques found in the published literature for rollover testing and rollover crashworthiness evaluation at the vehicle and component levels. It is not a comprehensive literature review, but rather illustrates the techniques that are in use or have been used to evaluate rollover crashworthiness-related issues.
Technical Paper

Occupant Friction Coefficients on Various Combinations of Seat and Clothing

2009-06-11
2009-01-1672
This paper reports on tests conducted to determine static and dynamic coefficients of friction between occupant clothing and automotive seat upholstery materials. Multiple materials were used for both the occupants clothing and the seat upholstery to examine friction variations with various material combinations. A fixture was fabricated to hold an automotive seat stationary while a dummy was pulled forward off of the seat. The forces required to pull the dummy were recorded for the various upholstery and clothing materials and the coefficients of friction were determined.
Journal Article

Nonlinear Optimization in Vehicular Crash Reconstruction

2015-04-14
2015-01-1433
This paper presents a reconstruction technique in which nonlinear optimization is used in combination with an impact model to quickly and efficiently find a solution to a given set of parameters and conditions to reconstruct a collision. These parameters and conditions correspond to known or prescribed collision information (generally from the physical evidence) and can be incorporated into the optimized collision reconstruction technique in a variety of ways including as a prescribed value, through the use of a constraint, as part of a quality function, or possibly as a combination of these means. This reconstruction technique provides a proper, effective, and efficient means to incorporate data collected by Event Data Recorders (EDR) into a crash reconstruction. The technique is presented in this paper using the Planar Impact Mechanics (PIM) collision model in combination with the Solver utility in Microsoft Excel.
Technical Paper

Challenges in Simulation and Sensor Development for Occupant Protection in Rollover Accidents

2000-11-01
2000-01-C038
Automotive occupant safety continues to evolve. At present this area has gathered a strong consumer interest which the vehicle manufacturers are tapping into with the introduction of many new safety technologies. Initially, individual passive devices and features such as seatbelts, knee- bolsters, structural crush zones, airbags etc., were developed for to help save lives and minimize injuries in accidents. Over the years, preventive measures such as improving visibility, headlights, windshield wipers, tire traction etc., were deployed to help reduce the probability of getting into an accident. With tremendous new research and improvements in electronics, we are at the stage of helping to actively avoid accidents in certain situations as well as providing increased protection to vehicle occupants and pedestrians.
Technical Paper

Essential Considerations in Delta-V Determination

2001-10-01
2001-01-3165
While Delta-V has been one of the most used indicators of accident severity for vehicle occupants, its actual determination remains a mystery to many who refer to it and use it. Delta-V is a term of art applied to a rapid change in vehicle velocity caused by impact forces during a collision. The Delta-V is associated with the high decelerations, which cause it and are applied to the occupants through restraint systems and collisions with the interior of the vehicle. This paper will serve as a primer for those new to the subject and a review for those who are familiar with the subject. Previous works by the authors will be referenced and other pertinent literature and data sources will be discussed. The analytical methods and test data used to calculate Delta-V will be presented and the relationship between Delta-V and other measures of impact severity, such as Barrier Equivalent Velocity and Energy Equivalent Speed will be discussed. The use of air bag sensor data will be included.
Technical Paper

ASSESSMENT OF THE USE OF SEAT BELTS IN BUSES BASED ON RECENT ROAD TRAFFIC ACCIDENTS IN SPAIN

2001-06-04
2001-06-0019
The most important topic in the field of passive safety of buses and coaches nowadays is the future compulsory use of seat belts. The objective of the study performed by IDIADA AUTOMOTIVE TECHNOLOGY SA and CENTRO ZARAGOZA is to make an important contribution to the existing technical data about this subject. This paper is based on the in-depth analysis of recent road traffic accidents where buses were involved. The first step is the accident reconstruction. A complete injury report including description and causes of occupant injuries is the basis for the correlation of a computer simulation model. Experience in the development of coach seats equipped with seat belts enables the preparation of a comparative model. The hypothesis that the consequences of the accident could have been less severe if the occupants of the bus had worn a seat belt can be evaluated. The conclusions will help the legislators make the right decision.
Technical Paper

Modeling the Effects of Seat Belt Pretensioners on Occupant Kinematics During Rollover

2006-04-03
2006-01-0246
The results of a number of previous studies have demonstrated that seat-belted occupants can undergo significant upward and outward excursion during the airborne phase of vehicular rollover, which may place the occupant at risk for injury during subsequent ground contacts. Furthermore, testing using human volunteers, ATDs, and cadavers has shown that increasing tension in the restraint system prior to a rollover event may be of value for reducing occupant displacement. On this basis, it may be argued that pretensioning the restraint system, utilizing technology developed and installed primarily for improving injury outcome in frontal impacts, may modify restrained occupant injury potential during rollover accidents. However, the capacity of current pretensioner designs to positively impact the motion of a restrained occupant during rollover remains unclear.
Technical Paper

Design and Evaluation of an Affordable Seatbelt Retrofit for Motor Coach Occupant Safety

2017-01-10
2017-26-0018
Prevention of passenger ejection from motor coach seats in the case of rollover and frontal crashes is critical for minimizing fatalities and injuries. This paper proposes a novel concept of affordably retrofitting 3-point seatbelts to protect passengers during these significant crash scenarios. Currently, the available options involve replacement of either the entire fleet, which takes time to avoid extremely high costs, or all seats with new seats that have seatbelts which is still expensive. Alternatively, this paper presents the development of an innovative product that can be installed in seat belt-ready bus structures at a fraction of the cost. The efficacy of the design is studied using finite element analysis (FEA) to meet Federal Motor Vehicle Safety Standards (FMVSS) 210 standards for conditions involved in frontal and side impacts.
Technical Paper

Effectiveness of Side-Airbags for Front Struckside Belted Car Occupants in Lateral Impact Conditions - An In-Depth-Analysis by GIDAS1

2007-04-16
2007-01-1157
Accident documentations on GIDAS (German In-Depth-Accident Study) from 1999 to 2005 are used for this study dealing with the effectiveness of the side airbag protection for car occupants. An analysis of real world accidents was carried out by ARU-MUH (Accident Research Unit - Medical University Hannover). The data were collected based on the spot documentation in time after an accident event. Based on the accident sampling process, the results of this study are representative for the German traffic accident situation. In order to determine the influence and the effectiveness of airbags, only those accident configurations with comparable conditions on impact direction are used for the study, therefore only cases with impact to the compartment, a delta-v-range 5 to 50 km/h and for struckside seated belted occupants were selected.
Technical Paper

The CREST project accident data base

2001-06-04
2001-06-0042
The protection of children in cars is improving with the increasing use of better designed restraint systems. Indeed, when children are correctly restrained in appropriate child restraint systems (CRS) they are sufficiently well protected in moderate frontal impacts. However, the levels of protection afforded in severe frontal impacts and lateral crashes has needed further attention. The CREST project, funded by the European Commission, was initiated to develop the knowledge on the kinematics behavior and tolerances of children involved in car crashes. The final aim of the project is to propose enhanced test procedures for evaluating the effectiveness of child restraint systems (CRS). The method used in this project was to collect data from accident investigations and from reconstructed crashes in order to determine the physical parameters (measured on dummies) which correspond to various injury mechanisms, and is described in ESV 2001 - paper n°294.
Technical Paper

An Investigation into C-NCAP AEB System Assessment Protocol

2017-09-23
2017-01-2009
In order to speed up the development of vehicle active safety technology in China, C-NCAP plans to add AEB and AEB VRU system as assessment items in 2018. With the purpose of studying the assessment protocol of AEB system, we have carried out 400,000 km road information collection and then we acquired the statistics of the operation conditions of dangerous situations. Combined with the traffic accident data collected by CIDAS, we found that the dangerous situations that we usually met were mainly three types, that was CCRs, CCRm and CCRb. Based on what we mentioned above, we analyzed the three kinds of working conditions and gave the corresponding evaluation method. In addition, combined with the actual situation of China, we added two tests of error function. And then we took the actual road experiment of many models of vehicles.
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