UNIVERSITY FOCUS Why OOP testing is vital Legislative protocols require manufacturers of automotive components to perform a series of tests before a product is launched. The test described here was done on commercial seats that were highly scored. Simply by changing the angle of the impact, the entire biomechanics were altered. The biomechanics of the dummy during oblique tests are currently unknown, and there are no injury criteria tailored for such a test. Furthermore, limited biofidelity of the dummy does not provide sufficient measurement apparatus to fully measure the severity of such a scenario. As it was proved here, a frontal oblique impact causes the chest belt to hit the neck of the passenger. The more reclined the seat, the higher the belt hits the neck. With the seat fully reclined, the belt locked on the dummy’s jaw. Furthermore, injury criteria associated with a rear impact are only valid for the sagittal plane. The BioRID dummy has spine motion only in the x-axis and the injury criteria require measurement only in this direction of motion. Today there are no injury criteria compatible with such complicated biomechanics, but for the development of autonomous cars, this is essential. rotation, which is one of the measurements that must be fulfilled in the FMVSS 202aD norm. Head-to-torso rotation is the angle of inclination of the head with respect to the angle of inclination of the chest. This, therefore, enables accurate measurements to be determined regardless of the initial position of the dummy. This measurement is adapted to the use of a Hybrid 3 dummy and is also one of the basic criteria in the FMVSS 202aD standard. The only difference is that FMVSS 202aD only considers the sagittal plane, while in OOP tests the resultant value is favored. It turns out that the greatest danger of spinal injury occurs during a rear oblique collision. Here the head-to-torso rotation reaches up to 90°. This leads to an over 93% chance of severe whiplash injury. Interestingly, the injury severity decreases depending on the angle of the seatback. The rear oblique impact with the dummy seated in a fully reclined seat has the lowest head-to-torso value. Nevertheless, this too is beyond the allowed limits. It is assumed that an angle above 12° is dangerous – and this is the limit value in the FMVSS 202aD standard. In this case, with the seatback fully reclined, the average value of the head-to-torso rotation is approximately 50°. In the event of a frontal oblique collision, the greater the inclination of the seatback, the greater the acceleration in the head, but it does not constitute a life-threatening injury. In this scenario, the larger the obliques, the greater the rotation of the head. of individual components of the dummy – for example, Out-of-position testing is becoming increasingly the pendulum test. Unfortunately, these certification tests popular and therefore it is necessary to create new test are not adapted to the kinetics that can occur during procedures. In addition, these types of tests often require OOP testing. Therefore, it is not certain that numerical modifications to the measuring instruments. The basic calculations will reflect reality. The computation may be dummies are not designed for testing in abnormal accurate because the models are getting more advanced, passenger positions. The criteria for neck injuries are but proving and verifying this is difficult for now. most accurately determined by the BioRID manikin, Nevertheless, development of automated vehicles will which considers the natural curvatures of the spine in not stop, and therefore any effort to improve the safety of its structure. However, it isn’t suitable for oblique tests. passengers in such cars is fully justified. The results of Taking into account the rapid the work conducted here are to be published development of computing power and in a research paper. Research of this type is Aleksander Górniak is an newer and more advanced computing currently terra incognita – but that is why assistant professor at Wrocław University of Science and programs, numerical models can be used. every contribution made to passive safety Technology and head of the However, each numerical model of the brings the team even more satisfaction. Laboratory of Vehicle Dynamics dummy must be validated definitively. This and Safety, which is part of the validation is usually carried out based on *Visit the website to access CTTI ’s archive GEO 3EM Research Complex standard crash tests or certification tests of back issues 48 JUNE 2024 “It turns out that the greatest danger of spinal injury occurs during a rear oblique collision” ABOVE AND INSET: Researchers at the Laboratory of Vehicle Dynamics and Safety have access to a wealth of cutting-edge analysis equipment www.AutomotiveTestingTechnologyInternational.com