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Upcoming test procedures and regulations consider the use of Q-dummies. Especially Q6 and Q10 will be introduced to assess the safety of child occupants in vehicle rear seats. Therefore detailed knowledge of these dummies is important to improve safety. As recent studies have shown, chest deflection measurements of both dummies are influenced by parameters like belt geometry. This could lead to a non optimized design of child restraint systems (CRS) and belt systems. The objective of this study is to obtain a more detailed understanding of the sensitivity of chest measurements to restraint parameters and to investigate the possibilities of chest acceleration as an alternative for the assessment of chest injury risks. A study of frontal impact sled tests was performed with Q6 and Q10 in a generic rear seat environment on a bench. Belt parameters like modified belt attachment locations were varied. For the Q6 dummy, different positioning settings of the CRS (booster with backrest) and of the dummy itself were investigated. The Q10 dummy was seated on a booster cushion. Here the position of the upper belt anchorage point was varied. To simulate the influence of vehicle rotation in the ODB crash configuration, the bench was pre-rotated on the sled in additional tests with the Q10. This configuration was tested with and without pretensioner and load limiter. Chest deflection in Q6 showed a high sensitivity to changes in positioning of the CRS and the dummy itself. A more slouched position of the CRS or dummy resulted in a reduction of measured chest deflection, whereas chest acceleration increased for a more slouched position of the CRS. Chest deflection in Q10 is sensitive to belt geometry as already shown in other studies. In a more outboard position of the shoulder belt anchorage the measured chest deflection is higher. Chest acceleration shows the opposite tendency, which is highest for the rearmost location of the upper belt anchorage. On a pre-rotated bench the highest chest deflection within this test series was observed without load limiter/pretensioner and an outboard belt position. By optimizing the belt location and the use of pretensioner/load limier the chest deflection was significantly reduced. For the Q6 a criterion based on chest acceleration as well as deflection measured at two locations might be the most reliable approach, which requires further research with an additional upper deflection sensor. In the Q10 the measured chest deflection does not always correctly reflect the severity of chest loading. The deflection is depending on initial belt position and restraint parameters as well as test conditions, which result in different directions of belt migration. A3ms chest acceleration might be a better indicator for severity of chest loading independent of different conditions like belt geometries. However, in some cases the benefit of an optimized restraint system could only be shown by deflection. These findings suggest that further research is needed to identify a chest injury assessment method, which could be based on deflection as well as acceleration or other parameters related to belt to occupant interaction.
Frontal impact is still the most relevant impact direction in terms of injury causation amongst car occupants. Especially for car-to-car frontal impacts the mass ratio between the involved vehicles has a significant impact on the injury risk (the heavier the opponent car the higher the injury risk). In order to address this issue frontal Mobile Deformable Barrier test procedures have been developed world-wide (for example the MPDB procedure that was fully described during the FIMCAR Project). The objective of this study was to investigate how vehicles of different weight classes perform in a mobile barrier test procedure compared to a fixed barrier test procedure (the full width rigid and offset deformable barrier test). Beyond that, the influence of vehicle mass and vehicle deformation on injuries was evaluated based on real world accident data. Five vehicle types were selected and tested in a fixed offset test procedure (ODB), a full width rigid barrier test procedure (FWRB) and a mobile offset test procedure (MPDB). For the accident analyses data from the German In-Depth Accident Study (GIDAS) was evaluated with a focus on MAIS 2+ injured belted front row car (UN-R 94 compliant cars) occupants in frontal impact accidents. Test data indicates higher dummy loadings, in particular for the head acceleration and chest acceleration, in the MPDB test for the vehicles with a mass lighter than the trolley (1,500 kg) compared to the FWRB test. The trend of increased vehicle stiffness (especially illustrated by tests with the MPDB and small cars) shows the need of a further improvement of passive restraint systems to reduce the occupant loading and with it the injury risk. The analyzed GIDAS data confirm the higher injury risk for occupants in cars with an accident weight of less than 1,500 kg compared to those with a crash weight above 1,500 kg in car-to-car and car-to-object or car-to-HGV, respectively. Furthermore the injury risk increases with decreasing mass ratio (i.e., the opponent car is heavier) in car-to-car accidents. Independent from the higher injury risk, the risk for passenger compartment intrusion in frontal impact appears not to be independent on the crash weight of the car.
Schutz von Fahrzeuginsassen
(1983)
Ausgehend von unfallstatistischen Daten und Ausführungen über Unfallablauf und Unfallfolgen werden Schutzmaßnahmen diskutiert, die das Verletzungsrisiko für Fahrzeuginsassen möglichst niedrig halten. Die Wirksamkeit von Schutzmaßnahmen wird beeinflusst von der Unfallkonstellation, Eigenschaften der Pperson und vom Fahrzeug (Deformationscharakteristik, Auslegung des rückhaltesystems). Die Gesamtwirksamkeit hängt wiederum ab von der Wirksamkeit des Rückhaltesystems, der Benutzungshäufigkeit und der Benutzungsqualität. Die Arbeit endet mit volkswirtschaftlichen Überlegungen und kommt zu dem Schluss, dass auch in Zukunft als wichtigste Maßnahme zum Schutz von Fahrzeuginsassen die Erhöhung der Anlegequote für Sicherheitsgurte anzusetzen ist.
One main objective of the EU-Project SENIORS is to provide improved methods to assess thoracic injury risk to elderly occupants. In contribution to this task paired simulations with a THOR dummy model and human body model will be used to develop improved thoracic injury risk functions. The simulation results can provide data for injury criteria development in chest loading conditions that are underrepresented in PMHS test data sets that currently proposed risk functions are based on. To support this approach a new simplified generic but representative sled test fixture and CAE model for testing and simulation were developed. The parameter definition and evaluation of this sled test fixture and model is presented in this paper. The justification and definition of requirements for this test set-up was based on experience from earlier studies. Simple test fixtures like the gold standard sled fixture are easy to build and also to model in CAE, but provide too severe belt-only loading. On the other hand a vehicle buck including production components like airbag and seat is more representative, but difficult to model and to be replicated at a different laboratory. Furthermore some components might not be available for physical tests at later stage. The basis of the SENIORS generic sled test set-up is the gold standard fixture with a cable seat back and foot rest. No knee restraint was used. The seat pan design was modified including a seat ramp. The three-point belt system had a generic adjustable load limiter. A pre-inflated driver airbag assembly was developed for the test fixture. Results of THOR test and simulations in different configurations will be presented. The configurations include different deceleration pulses. Further parameter variations are related to the restraint system including belt geometry and load limiter levels. Additionally different settings of the generic airbag were evaluated. The test set-up was evaluated and optimized in tests with the THOR-M dummy in different test configurations. Belt restraint parameters like D-ring position and load limiter setting were modified to provide moderate chest loading to the occupant. This resulted in dummy readings more representative of the loading in a contemporary vehicle than most available PMHS sled tests reported in the literature. However, to achieve a loading configuration that exposes the occupant to even less severe loading comparable to modern vehicle restraints it might be necessary to further modify the test set-up. The new generic sled test set-up and a corresponding CAE model were developed and applied in tests and simulations with THOR. Within the SENIORS project with this test set-up also volunteer and PMHS as well as HBM simulations are performed, which will be reported in other publications. The test environment can contribute in future studies to the assessment of existing and new frontal impact dummies as well as dummy improvements and related instrumentation. The test set-up and model could also serve as a new standard test environment for PMHS and volunteer tests as well as HBM simulations.
Europe has benefited from a decreasing number of road traffic fatalities. However, the proportion of older road users increases steadily. In an ageing society, the SENIORS project aims to improve the safe mobility of older road users by determining appropriate requirements towards passive vehicle safety systems. Therefore, the characteristics of road traffic crashes involving the elderly people need to be understood. This paper focuses on car occupants and pedestrians or cyclists in crashes with modern passenger cars. Ten crash databases and four hospital statistics from Europe have been analysed to answer the questions on which body regions are most frequently and severely injured in the elderly, and specific injuries sustained by always comparing older (65 years and above) with midâ€aged road users (25â€64 years). It was found that the body region thorax is of particularly high importance for the older car occupant with injury severities of AIS2 or AIS3+, where as the lower extremities, head and the thorax need to be considered for older pedestrians and cyclists. Further, injury risk functions were provided. The hospital data analysis showed less difference between the age groups. The linkage between crash and hospital data could only be made on a general level as their inclusion criteria were quite different.
A reduction of around 48% of all road fatalities was achieved in Europe in the past years including a reduced number of fatalities with an older age. However, among all road fatalities, the proportion of elderly is steadily increasing. In an ageing society, the European (Horizon2020) project SENIORS aims to improve the safe mobility of older road users, who have different transportation habits compared to other age groups. To increase their level of safe mobility by determining appropriate requirements for vehicle safety systems, the characteristics of current road traffic collisions involving the elderly and the injuries that they sustain need to be understood in detail. Hereby, the paper focuses on their traffic participation as pedestrian, cyclist or passenger car occupant. Following a literature review, several national and international crash databases and hospital statistics have been analysed to determine the body regions most frequently and severely injured, specific injuries sustained and types of crashes involved, always comparing older road users (65 years and more) with mid-aged road users (25-64 years). The most important crash scenarios were highlighted. The data sources included European statistics from CARE, data on national level from Germany, Sweden, Italy, United Kingdom and Spain as well as in-depth crash information from GIDAS (Germany), RAIDS (UK), CIREN and NASS-CDS (US). In addition, familiar hospital data from Germany (TraumaRegister DGU-®), Italy (Italian Register of Acute Traumas) and UK hospital statistics (TARN) were included in the study to gain further insight into specific injury patterns. Comprehensive data analyses were performed showing injury patterns of older road users in crashes. When comparing with mid-aged road users, all databases showed that the thorax body region is of particularly high importance for the older car occupant with injury severities of AIS 2 or AIS 3+, whereas the body regions lower extremities, head and thorax need to be considered for the older pedestrians and cyclists. Besides these comparisons, the most frequent and severe top 5 injuries were highlighted per road user group. Further, the most important crash configurations were identified and injury risk functions are provided per age group and road user group. Although several databases have been analysed, the picture on the road safety situation of older road users in Europe was not complete, as only Western European data was available. The linkage between crash data and hospital data could only be made on a general level as their inclusion criteria were quite different.
Car occupants have a high level of mortality in road accidents, since passenger cars are the prevalent mode of transport. In 2013, car occupant fatalities accounted for 45% of all road accident fatalities in the EU. The objective of this research is the analysis of basic road safety parameters related to car occupants in the European countries over a period of 10 years (2004-2013), through the exploitation of the EU CARE database with disaggregate data on road accidents. Data from the EU Injury Database for the period 2005 - 2008 are used to identify injury patterns, and additional insight into accident causation for car occupants is offered through the use of in-depth accident data from the EC SafetyNet project Accident Causation System (SNACS). The results of the analysis allow for a better understanding of the car occupants' safety situation in Europe, thus providing useful support to decision makers working for the improvement of road safety level in Europe.
In most of developed countries, the progress made in passive safety during the last three decades allowed to drastically reduce the number of killed and severely injured especially for occupants of passenger cars. This reduction is mainly observed for frontal impacts for which the AIS3+ injuries has been reduced about 52% for drivers and 38% for front passengers. The stiffening of the cars' structure coupled with the generalization of airbags and the improvement of the seatbelt restraint (load limiter, pretension, etc.) allowed to protect vital body regions such as head, neck and thorax. However, the abdomen did not take advantage with so much success of this progress. The objective of this study is to draw up an inventory on the abdominal injuries of the belted car occupants involved in frontal impact, to present adapted counter-measures and to assess their potential effectiveness. In the first part the stakes corresponding to the abdominal injuries will be defined according to types of impact, seat location, occupants' age and type of injured organs. Then, we shall focus on the abdominal injury risk curves for adults involved in frontal impact and on the comparisons of the average risks according to the seat location. In the second part we will list counter-measures and we shall calculate their effectiveness. The method of case control will be used in order to estimate odds ratio, comparing two samples, given by occupants having or not having the studied safety system. For this study, two type of data sources are used: national road injured accident census and retrospective in-depth accident data collection. Abdominal injuries are mainly observed in frontal impact (52%). Fatal or severe abdominal occupant- injuries are observed at least in 27% of cases, ranking this body region as the most injured just after the thorax (51%). In spite of a twice lower occupation rate in the back seats compared to the front seats, the number of persons sustaining abdominal injuries at the rear place is higher than in the front place. In recent cars, the risk of having a serious or fatal abdominal injury in a frontal impact is 1.6% for the driver, 3.6% for the front passenger and 6.3% for the rear occupants. The most frequently hurt organs are the small intestine (17%), the spleen (16%) and the liver (13%). The most common countermeasures have a good efficiency in the reduction of the abdominal injuries for the adults: the stiffness of the structure of the seats allows decreasing the abdominal injury risk from 54% (driver) to 60% (front occupant), the seatbelt pretensioners decrease also this risk from 90% (driver) to 83% (front passenger).
In this study, we compared the injury severity of occupants according to the seating position and the crashing direction in motor vehicle accidents. In the driver's point of view, it was separated the seating position as "Near-side" and "Far-side". The study subjects were targeted by people who visited 4 regional emergency centers following motor vehicle accidents. Real-world investigation was performed by direct and indirect methods after patient- consent. The information of the damaged vehicle was informed by Collision Deformation Classification (CDC) code and the information of the injury of patients was informed by using the Abbreviated Injury Score (AIS) and Injury Severity Score (ISS). When the column 3 in CDC code was P, damaged at the middle part of lateral side, the average point of AIS 3 was 1.91-±1.72 in near-side and 1.02-±1.31 in far-side (p<0.01). The average point of maximum AIS (MAIS) was 2.78-±1.39 in near-side and 2.02-±1.11 in far-side (p<0.01). The average point of ISS was 15.74-±14.71 in near-side and 8.11-±8.39 in far-side (p<0.01). Also, when the column 3 in CDC code was D, damaged at the whole part of lateral side, it was significant that the average point of AIS 3 and MAIS in near-side was bigger than in far-side (p=0.02).
From an automotive safety occupant protection standpoint, effective occupant restraint requires a system capable of providing non-injurious occupant ride down of anticipated crash forces. This is not only the case for frontal collisions, where occupant restraint is provided primarily by seatbelts and airbags, but is also critical for other crash modes such as side impacts, rear impacts, rollovers, as well as multiple impact events. In the rear impact crash mode, occupant restraint is provided primarily by the seatbacks and to some extent the seatbelts. Foundationally, therefore, what becomes fundamental to the seatback's role in rear occupant protection is its ability to contain the occupant within the seat, preventing occupant ramping, as well as preventing the seat's, and/or its occupant's, dangerous intrusion into the rear occupant's survival space where contact with rear compartment components and/ or rear seated occupants can present a significant injury risk. An analysis is presented of a series of rear impact sled testing conducted by the authors that evaluates the timing, position and extent of the front seatback's reward displacement toward and into the rear occupant compartment as well as consideration of the front seat occupant' ramping potential and its injury potential relative to the rear compartment. Additionally, three other series of testing are presented which assess various seat designs occupant retention capabilities. Lastly, a matched-pair comparison test series is presented which evaluates occupant motion in rear impact with and without use of a typical vehicle body mounted 3-point seatbelt. Discussion of restraint system performance observed in all the testing is included along with ATD biofidelity and thigh-gap considerations. The data collected and presented includes accelerometer instrumentation and high speed video analysis.