The introduction of the IIHS Small Overlap test configuration implies a more severe and critical load case at the structural parts of the vehicle that need more improvement. In 2012 IIHS began to evaluate the vehicles crashworthiness with the small overlap tests due to a recent crashworthiness study in the EU and USA that found a higher severity in frontal crashes. The result showed that occupant injuries and vehicle structure deformation were severe when the vehicle was loaded outboard (Small Overlap).
In order to have a better knowledge of the cinematics of this new test, several crash test
and crash- worthiness analysis were carried out. Applus+ IDIADA identified the lack of knowledge about how vehicles react to SOI impact. Identifying the forces applied in each structural element involved in order to help the manufacturers with vehicle development was very important and due to that a Small overlap barrier able to record forces was built.
An instrumented barrier helps to correlate simulation and improve elements in order to reduce cage intrusion and reduce occupant injuries. This barrier obtains force information of each important structural vehicle element as hinge pillar, footwell, rocker panel during the crash test. The barrier was instrumented with a tri-axial load cells at the center of the barrier and the corner.
The aim of this study was to implement a better acquisition system, especially the cor-ner. Also study the test severity and intrusion, analyzing the forces involved and the structural vehicle elements in order to improve the design strategies
Method and Material
A Small Overlap test was carried out. The setup was a vehicle at 64.4 km/h against a rigid barrier with an overlap of 25%. The barrier was fully instrumented with load cells at the barrier’s center and also at the corner. The load cells at the barrier ware tri-axial in order to obtain information from the X, Y and Z axes, especially important to obtain data from the vehicle’ translation and rotation of the vehicle at the corner. After the tests, the data obtained was analyzed and graphics of energy, force, velocity and accelerations were made.
The study results show the importance of the wheel’s intrusion and the mechanism of deformation of other parts of the vehicle such as the sill beam, A-pillar and the shotgun at the Small Overlap test. With the corner’s instrumentation the total amount of energy was assessed and the mechanisms of absorption during the vehicle’s rotation at the corner were registered.
Vehicle manufacturers improved quite a lot the vehicle’s structure in order to protect the occupant in frontal crash but real crashworthiness determine that more countermeasures and improvements should be made. Providing more tools to manufacturers for design vehicles will help reducing deaths and severe injuries in vehicle occupants.