Study of Vehicle Dynamics and Occupant Response in Side Impact Crash Tests
Side impact crash is a leading cause of fatalities on the roadways of the industrialized world. In the mid 1990's NHTSA implemented a new car assessment program testing the lateral crashworthiness of vehicles entering the market with a moving deformable barrier. Previous work has been done in an attempt to distill these tests into finite element simulations using specific vehicle test results; however there has not been a comprehensive study attempting to develop a model that includes a large number of tests to evaluate trends in vehicle kinematics and how they affect the occupants coupled with finite element simulations. To this end, a study of side NCAP tests was performed on all sedan cars based on the test results reported in the NHTSA Vehicle Crash Test Database since the introduction of the 2005 model year. This data was used to evaluate typical motion of the target vehicle during a regulatory crash test, and the corresponding occupant response. This sample consisted of new models entering the market and nameplates with major redesigns with a sample size of 72 vehicles. From these tests a series of velocity profiles were developed including time versus average velocity plots for vehicle center of gravity, door sill, driver's seat and driver door. These parameters have been shown to be important in occupant response and injury. There was significant variability in the response at several accelerometer locations. It was also found that rotation of the vehicle did not become significant until after 100 ms, after the maximum injury was predicted by the dummy. A parametric finite element analysis was performed using the both the USSID and ES-2re models to study the response of a restrained occupant during a typical crash test. These simulations showed that the velocity of the intruding door had a large effect on the thoracic injury predicted by the side impact dummy models. The full text of this paper may be found at: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv21/09-0016.pdf For the covering abstract see ITRD E145407.
Analysis of Thoracic Loading, Kinematics, and Injuries in Small Overlap Impacts: Field Data and Full-Scale Vehicle Tests with Dummies
In the literature frontal crashes typically have been classified as full, large overlap, or small overlap impacts (SOI) in accordance with the degree of frontal area involvement. These classifications implicitly refer to the degree of longitudinal structure engagement during impact. While full and large overlap impacts have received considerable attention, SOI has undergone limited analyses through field and laboratory investigations. Limited structural engagements may expose occupants to increased intrusions and differing kinematics. The objective of this study was to summarize literature relevant to SOI, determine occupant injuries using CIREN data, and analyze occupant loading and motions using full-scale vehicle tests. CIREN results demonstrated lack of correlation between injury and typical crash severity parameters of ΔV, crush distance, and extent zone. Full-scale crash tests suggested that occupant kinematics in SOI may be unique among frontal impact configurations.
Development and Evaluation of the ES-2 Dummy
Over the last year, the European Enhanced Vehicle-safety Committee Working Group 12 has assessed and reviewed the performance of the enhanced anthropomorphic test device for lateral impacts, EUROSID-2 (ES-2). The objectives for this work have been the following: 
- To verify whether the proposed design is addressing the shortcomings of the regulatory test device EUROSID-1 as identified previously by EEVC and NHTSA
- To make sure that the original EUROSID-1 biofidelity and performance in normal test conditions is preserved. 
- To reach a well-balanced conclusion, the working group has undertaken a test program to assess the most important requirements for the ES-2 dummy, biofidelity, sensitivity, repeatability, handling, durability, certification and full-scale performance in comparison with EUROSID-1.

In addition, but no less important, the working group has reviewed and explored the findings of full-scale tests conducted at several member organisations within ACEA. ACEA has reported the most important findings in September 2000. Subsequently, WG 12 has further investigated the issues raised in this report. On the basis of this work, the working group has concluded the following with regards to the ES-2 specifications and performance:
The ES-2 prototype as tested is superior to current test device EUROSID-1 and, hence, a more appropriate test device for regulatory testing. The important shortcomings of the EUROSID-1 have been satisfactorily addressed with ES-2, whilst biofidelity is maintained, in some areas even somewhat improved. It should be noted, however, that the assessment of thorax biofidelity was based on deflection and force-time data only, and does not incorporate an assessment of V*C. It is recommended to adopt the hardware design without further modification and to use the new proposed certification procedures, with the exception of the high velocity pelvis test.
Overall test results in full-scale tests have shown that some critical dummy measurement values for ES-2 have increased compared to EUROSID-1, in particular rib deflection, 17%, and V*C, 23%1 on average. Other values on the other hand have brought down such as the pubic force (10%) due to improved leg interaction. Contrary to the full-scale results, the ES-2 gave equal or lower values for all critical measurements in the biofidelity tests.
For the large majority of vehicles tested, the different results would not affect pass or fail with respect to current regulatory limits. It should be noted, however, that, maintaining the rating levels in consumer testing, ES-2 results would lead motoring consumers to believe the protection offered in side impact has decreased while in fact the safety performance of these vehicles has not changed.
A force transducer has been developed to measure the force applied to the back plate. It is recommended to use the force transducer in full vehicle assessment.
Finally, the working group believes the ES-2 dummy forms a solid basis for interim harmonisation and will further support activities to help realise this objective.