Assessment of Abdominal Loading to Pregnant Model Setup during Vehicle Frontal Impact for Different Lap Belt Positions

The paper addresses the safety of a pregnant passenger from an injury risk point of view regarding to the position of the seatbelt’s lap part. The finite element based-pregnant abdomen model is incorporated into the simplified rigid body-based female body model. The study was done in two steps. Firstly, a female model was validated in the frontal sled test to ensure its biofidelity for this particular purpose. Secondly, a fully deformable abdomen was added to create a pregnant female model. Such model was positioned in a deformable frontal seat and restrained by a safety system such as a three-point seat belt and airbag to simulate the frontal sled test scenario. A deceleration pulse corresponding to a frontal impact related to two impact velocities (30 km/h and 50 km/h) is applied and the restraint system performance is assessed with the focus on the fetus and female injury risk. The main aim is to assess the influence of various lap belt positions over the belly on the loading of the pregnant female’s abdomen. The uterus is modelled via a so-called biobag and the mechanical loadings of this particular part and adjacent structures are the main output monitored in this study. The fetus itself is not included in the model; however, its loading is assessed via mechanical loading of the uterus.

Due to the lack of injury assessment data for the fetus and uterus respectively, only the mechanical loading of the abdominal structures was monitored. This paper concludes that incorrect use of the seat belt (position of the lap belt over the bump) leads to a higher loading of the abdomen.