| 1. |
- Strandroth, Johan, 1978, et al.
(författare)
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Correlation between Euro NCAP Pedestrian Test Results and Injury Severity in Injury Crashes with Pedestrians and Bicyclists in Sweden
- 2014
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Ingår i: SAE Technical Papers. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191 .- 2688-3627. ; 2014-November:November
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Tidskriftsartikel (refereegranskat)abstract
- Pedestrians and bicyclists account for a significant share of deaths and serious injuries in the road transport system. The protection of pedestrians in car-to-pedestrian crashes has therefore been addressed by friendlier car fronts and since 1997, the European New Car Assessment Program (Euro NCAP) has assessed the level of protection for most car models available in Europe. In the current study, Euro NCAP pedestrian scoring was compared with real-life injury outcomes in car-to-pedestrian and car-to-bicyclist crashes occurring in Sweden. Approximately 1200 injured pedestrians and 2000 injured bicyclists were included in the study. Groups of cars with low, medium and high pedestrian scores were compared with respect to pedestrian injury severity on the Maximum Abbreviated Injury Scale (MAIS)-level and risk of permanent medical impairment (RPMI). Significant injury reductions to both pedestrians and bicyclists were found between low and high performing cars. For pedestrians, the reduction of MAIS2+, MAIS3+, RPMI1+ and RPMI10+ ranged from 20-56% and was significant on all levels except for MAIS3+ injuries. Pedestrian head injuries had the highest reduction, 80-90% depending on level of medical impairment. For bicyclist, an injury reduction was only observed between medium and high performing cars. Significant injury reductions were found for all body regions. It was also found that cars fitted with autonomous emergency braking including pedestrian detection might have a 60-70% lower crash involvement than expected. Based on these results, it was recommended that pedestrian protection are implemented on a global scale to provide protection for vulnerable road users worldwide.
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| 2. |
- Tingvall, Claes, 1953, et al.
(författare)
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The consequences of adopting a MAIS 3 injury target for road safety in the EU: A comparison with targets based on fatalities and long-term consequences
- 2013
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Ingår i: International Research Council on the Biomechanics of Injury Conference, IRCOBI 2013. - : International Research Council on the Biomechanics of Injury. ; , s. 1-11, s. 1-11
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Konferensbidrag (refereegranskat)abstract
- It has been proposed in the European Union (EU) to adopt a Maximum Abbreviated Injury Scale (MAIS) of 3 or greater as the basis for a road safety target. To have a common definition of serious injury across the EU is in itself very positive. In this study, fatalities, MAIS 3+, MAIS 2+ and injuries leading to permanent medical impairment (PMI) were used to identify problem scenarios. A national data set of injuries reported to Swedish hospitals from 2007 to 2012 (STRADA) was used. Police-reported injuries were also taken into account. The results showed that, depending on the data source and injury rating method, problem scenarios differed substantially. While fatalities were dominated by vehicle occupants in high-speed environments, vulnerable road users in urban areas were in greater focus as a result of lowered thresholds for injury or impairment levels. Bicyclists in particular have many injuries at less severe, yet significant, levels. There is a particular need to consider certain diagnoses which lead, relatively often, to long-term consequences at the AIS 1 level. To achieve a better injury and consequence scenario, data from the medical system are an essential prerequisite.
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| 3. |
- Bálint, András, 1982, et al.
(författare)
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A test-based method for the assessment of pre-crash warning and braking systems
- 2013
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Ingår i: Accident Analysis and Prevention. - : Elsevier BV. - 0001-4575. ; 59, s. 192-199
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a test-based assessment method for pre-crash warning and braking systems is presented where the effectiveness of a system is measured by its ability to reduce the number of injuries of a given type or severity in car-to-car rear-end collisions. Injuries with whiplash symptoms lasting longer than 1 month and MAIS2+ injuries in both vehicles involved in the crash are considered in the assessment. The injury reduction resulting from the impact speed reduction due to a pre-crash system is estimated using a method which has its roots in the dose–response model. Human–machine interaction is also taken into account in the assessment. The results reflect the self-protection as well as the partner-protection performance of a pre-crash system in the striking vehicle in rear-end collisions and enable a comparison between two or more systems. It is also shown how the method may be used to assess the importance of warning as part of a pre-crash system.
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| 4. |
- Carlsson, Anna K, 1966, et al.
(författare)
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Anthropometric Specifications, Development, and Evaluation of EvaRID : A 50th Percentile Female Rear Impact Finite Element Dummy Model
- 2014
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Ingår i: Traffic Injury Prevention. - : Taylor & Francis. - 1538-9588 .- 1538-957X. ; 15:8, s. 855-865
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Whiplash-associated disorders (WADs), or whiplash injuries, due to low-severity vehicle crashes are of great concern in motorized countries and it is well established that the risk of such injuries is higher for females than for males, even in similar crash conditions. Recent protective systems have been shown to be more beneficial for males than for females. Hence, there is a need for improved tools to address female WAD prevention when developing and evaluating the performance of whiplash protection systems. The objective of this study is to develop and evaluate a finite element model of a 50th percentile female rear impact crash test dummy.Methods: The anthropometry of the 50th percentile female was specified based on literature data. The model, called EvaRID (female rear impact dummy), was based on the same design concept as the existing 50th percentile male rear impact dummy, the BioRID II. A scaling approach was developed and the first version, EvaRID V1.0, was implemented. Its dynamic response was compared to female volunteer data from rear impact sled tests.Results: The EvaRID V1.0 model and the volunteer tests compared well until ~250 ms of the head and T1 forward accelerations and rearward linear displacements and of the head rearward angular displacement. Markedly less T1 rearward angular displacement was found for the EvaRID model compared to the female volunteers. Similar results were received for the BioRID II model when comparing simulated responses with experimental data under volunteer loading conditions. The results indicate that the biofidelity of the EvaRID V1.0 and BioRID II FE models have limitations, predominantly in the T1 rearward angular displacement, at low velocity changes (7 km/h). The BioRID II model was validated against dummy test results in a loading range close to consumer test conditions (EuroNCAP) and lower severity levels of volunteer testing were not considered.The EvaRID dummy model demonstrated the potential of becoming a valuable tool when evaluating and developing seats and whiplash protection systems. However, updates of the joint stiffness will be required to provide better correlation at lower load levels. Moreover, the seated posture, curvature of the spine, and head position of 50th percentile female occupants needs to be established and implemented in future models.
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| 5. |
- Carlsson, Anna K, 1966, et al.
(författare)
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EvaRID : A 50th percentile female rear impact finite element dummy model
- 2012
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Ingår i: 2012 IRCOBI Conference Proceedings. ; , s. 249-262, s. 249-262
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Konferensbidrag (refereegranskat)abstract
- Neck injury due to low severity vehicle crashes is of worldwide concern and the injury risk is greater for females than males. However, whiplash protection systems have shown to be more beneficial for males than females. Hence there is a need for improved tools to address female protection. The objective is to develop and evaluate a 50th percentile female rear impact crash dummy FE model. The model was based on the same design concept as the BioRID II. A scaling approach was developed and the first version, EvaRID V1.0, was implemented. Its dynamic response was compared to rear impact tests with female volunteers. The EvaRID model and volunteer tests showed good correlations until 250 ms of the head and T1 accelerations, linear displacements and head angular displacement. Considerably less T1 angular displacement was found for the EvaRID; similar results were obtained for the BioRID II. Thus, the EvaRID V1.0 and BioRID II models have limitations at low ÎŽv (7km/h). The EvaRID model demonstrated the potential to become a valuable tool when evaluating and developing seats/whiplash protection systems, however, this will require updating the joint stiffness. The model may be used as a template for the development of a physical female dummy.
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| 6. |
- Davidsson, Johan, 1967, et al.
(författare)
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Evaluation of Seat Performance Criteria for Future Rear-end Impact Testing
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In the past, EEVC WG12 and 20 have evaluated rear-impact dummies and reviewed associated injury criteria and assessment reference values for seat performance evaluations (Hynd et al. 2007 and Hynd and Carroll 2008). The BioRID II was recommended to be used in future legislative dynamic rear-end impact seat performance tests. Recommended injury criteria and assessment reference values to be used with the dummy are however still pending. This is mainly due to the incomplete understanding of the injury site and mechanisms responsible for the symptoms presented after such impacts. This lack of biomechanical data limits the possibility to evaluate any proposed injury criteria and associated reference values. The aim of this study is to address these limitations by comparing crash test dummy parameter values from performed sled tests with real-life accident data. The results are expected to indicate the injury predictability of the complete sled test method, which includes performance criteria, the use of a generic sled acceleration pulse, the use of the BioRID II and its current positioning procedure. Real-life injury risk was calculated for 32 individual car models and for 17 groups of similar seat designs from data provided by Folksam. When grouped data was introduced, i.e. by dividing applicable data into groups with similar seat designs, the reliability of the insurance data was raised, while the dummy measurements remained constant. The number of insurance cases ranges from 32 to 1023 for individual car models and from 132 to 1023 for groups with similar seat designs. Regression coefficients (r2) were calculated and the data presented graphically. Two types of injury risks were used in this study: those that had documented symptoms for more than one month and those that were classified as a permanent medical impairment as the consequence of a rear-end impact. These injury risks were compared to crash test dummy parameter values from sled tests performed with a BioRID II in 16 km/h medium Euro-NCAP pulse. It was found that the analysis of groups of similar seat designs provided the most reliable results. Analysing individual data clearly showed that the insurance cases were too low per seat model to be used in an evaluation of seat performance criteria. In conclusion, the results obtained in the analysis of individual data did not invalidate the results obtained using grouped datasets. This conclusion was based on the observation that the correlations found in the analysis of grouped datasets could exist also for individual car model data.When comparing groups of seats, the analysis showed that the Neck Injury Criterion (NIC), the maximum rearward Occipital Condyle x-displacements in a coordinate system that moves with the T1 and the maximum L1 x-acceleration were the parameters that best predicted the risk of developing permanent medical impairment, and symptoms for more than one month given that the occupant had initial symptoms following a rear-end impact. The maximum rearward head rel. T1 angular displacement, T1 x-acceleration and upper neck shear load (U.N.Fx, head r.w.) were parameters that also could predict the risk of permanent medical impairment and symptoms for more than one month. These results are supported by recent studies. In comparison with a previous report, this study includes additional seat tests data which allowed additional data points to be included in the regression analysis. An expanded insurance claim database, about three times more insurance claims, was included in the analysis, which made the results more reliable. The insurance data was compensated for differences in the definitions of short term symptoms and permanent medical impairment during the accident data sampling period. This reduced errors that could have been introduced by the market share change during the sampling period for the various vehicle models included in this study. In the future, a logistic regression including error estimation that covers all available insurance and test data should be carried out. The advantage of such an analysis would be that data could be included independent of the number of accidents. Another advantage of this is that a larger proportion of the data would be from tests and real life accidents with newer cars than those included in this study. Therefore the recommended parameters to use in seat evaluations would be more suitable for modern car seat systems.
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| 7. |
- Davidsson, Johan, 1967, et al.
(författare)
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Evaluation of Seat Performance Criteria for Rear-End Impact Testing
- 2011
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Ingår i: 22nd International Technical Conference on the Enhanced Safety of Vehicles, Washington DC, Gaylord National Conference Convention Centre, June 13 – 16, 2011. ; 22:Paper Number 11-0373, s. 14-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The BioRID II has been recommended to be used in future legislative dynamic rear-end impact seat performance tests. Recommended injury criteria and assessment reference values to be used with the dummy is however still pending. This is mainly due to the incomplete understanding of the injury site and mechanisms responsible for the symptoms presented after such impacts. This lack of biomechanical data limits the possibility to evaluate any proposed injury criteria and associated reference values. The aim with this study is to address these limitations by comparing crash test dummy parameter values from performed sled tests with real-life accident data. The results are expected to indicate the injury predictability of the complete sled test method, which includes performance criteria, the use of generic sled acceleration pulse, the use of the BioRID II and its current positioning procedure, etc. Real-life injury risk was calculated for groups with similar seat designs from data provided by Folksam. By introducing grouped data, i.e. by dividing applicable data into groups with similar characteristics, the reliability of the insurance data increased while the dummy measurements remained constant. Two different injury risks were used in this study; those that had documented symptoms for more than 1 month and those that were classified as a permanent impairment as the consequence of a rear-end impact. The injury risks for the groups were compared to single crash test dummy parameter values from sled tests performed with a BioRID II in 16 kph medium Euro-NCAP pulse. In the comparison, 12 seat groups were compared with 6665 insurance cases (range from 94 to 1575 cases/group). Regression coefficients (R2) were calculated. The analysis of groups with similar seat design provided the most reliable results. The analysis showed that NIC, upper neck shear force, vertical head acceleration and lower neck bending moment were the parameters that best predicted the risk of developing permanent impairment given that the occupant had initial symptoms following a rear-end impact. Similarly, NIC, vertical head acceleration and lower neck moment were parameters that best predicted the risk of short term (> 1 month) symptoms. These results are supported by recent studies.
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| 8. |
- Davidsson, Johan, 1967, et al.
(författare)
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Evaluation of Seat Performance Criteria for Rear‐End Impact Testing BioRID II and Insurance Data
- 2013
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Ingår i: IRCOBI Conference. - 2235-3151. ; :IRC-13-15, s. 63-76
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Konferensbidrag (refereegranskat)abstract
- The BioRID is recommended for legislative rear‐end impact seat tests. Recommendedinjury criteria are, however, lacking; biomechanical data are limited and confines any evaluation ofproposed criteria.This study aimed at addressing these limitations by comparing BioRID II data from sled tests withreal‐life accident data. Results will evaluate injury predictability of the complete sled test method, whichincludes performance criteria, the use of a generic acceleration pulse, and the BioRID, etc.Real‐life injury risk was calculated for 17 groups of similar seat designs from data provided byFolksam. The number of insurance cases range from 150 to 1136 per group. Regression coefficientswere calculated. Two types of injury risks were used: those leading to documented symptoms of morethan one month’s duration and those classified as leading to permanent medical impairment as aconsequence of a rear‐end impact. These risks were compared to parameter values from sled testsperformed with a BioRID II at 16 km/h pulses.NIC, the maximum rearward Occipital Condyle relative T1 x‐displacements and L1 x‐acceleration bestpredicted the risk of developing permanent medical impairment and symptoms of more than onemonth, given the occupant had initial symptoms following a rear‐end impact.
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| 9. |
- Jonsson, Bertil, et al.
(författare)
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Development of Whiplash associated Disorders for adult and child occupants in cars launched since the 1980s in different impact directions
- 2011
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Ingår i: 2011 IRCOBI Conference Proceedings - International Research Council on the Biomechanics of Injury (;Krakow;14 -16 September 2011). - : International Research Council on the Biomechanics of Injury. ; , s. 62-72, s. 62-72
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Studies have shown that crashworthiness of cars addressing fatal and serious injuries has generally improved over time. However, the development regarding injuries leading to medical impairment has not been shown to the same extent. The objective was to investigate the development of Whiplash associated Disorders (WAD) leading to long-term consequences for adult front seat occupants and for children 0-12 years of age in cars introduced at different year intervals and in different impact directions separated for gender. Long-term consequences were defined as occupants with WAD symptoms at least one month and those resulting in medical impairment. The developments were studied for cars divided into intervals according to year of introduction and for frontal, side and rear-end impacts. All adult occupants (35 611) and 76% of all children (973) reporting WAD between 1998 and 2008 were selected. Approximately 2% of the children reporting initial symptoms sustained medical impairment. The corresponding figure for adult occupants was approximately 10%. Between the introduction years 1980-84 and 2000-04 the proportions of adult occupants with medical impairment dropped by approximately 70% (both males and females) in frontal and rear-end crashes, while the reduction in lateral impacts appears to be somewhat lower. For children there is a tendency that the proportion of WAD increases in newer models in frontal collisions. The result indicates that protecting children facing forward deserves more attention from the automotive industry and governmental bodies.
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| 10. |
- Kullgren, Anders, 1963, et al.
(författare)
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Development of whiplash associated disorders for male and female car occupants in cars launched since the 80s in different impact directions
- 2013
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Ingår i: International Research Council on the Biomechanics of Injury Conference, IRCOBI 2013. - : International Research Council on the Biomechanics of Injury. ; , s. 51-62, s. 51-62
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Konferensbidrag (refereegranskat)abstract
- The aim was to investigate the development of Whiplash Associated Disorders (WAD) leading to long-term consequences for drivers separated for gender in cars introduced at different year intervals and in different impact directions. An additional aim was to analyze the influence of various whiplash preventive concepts on WAD in rear impacts. The developments were studied for cars grouped into 5-year intervals according to year of introduction separated for frontal, side and rear-end impacts and for gender. All drivers (24,452) reporting WAD during the years 1998-2012, and those reporting symptoms > 1 month as well as those with permanent impairment, were included. Whiplash preventive concepts were grouped according to car make and concept. A reduction in risk of long-term consequences after reporting initial symptoms of WAD were found in rearend and side impacts comparing cars introduced on the market 1980-84 and 2005-2009. No reduction was found in frontal impacts. This clearly shows that more focus on preventive interventions for frontal impacts is needed. Existing seat concepts aimed at lowering the risk of WAD were found to reduce the risk of long-term consequences after reporting initial symptoms of WAD. However, seats with energy absorption in the seat back, passive seats or reactive seats are more effective for females than seats with Reactive Head Restraints, which showed no major reduction of WAD with long-term consequences compared with standard seats.
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