To mitigate the societal impact of motor vehicle crash, researchers are using a variety of tools, including human body finite element models (FEMs). Such models are often developed to represent a 50th percentile male occupant (M50). However, in order to address the effects of size and sex-related geometrical changes, there is interest in developing models of other driving cohorts. As part of the Global Human Body Models Consortium (GHBMC) project, comprehensive medical image and anthropometrical data of the 5th percentile female (F05) were acquired for the explicit purpose of FEM development. This multi-modality dataset was leveraged for the development of a posture specific CAD model of the F05.

The CAD dataset was then utilized for mesh development of the GHBMC F05 occupant (F05-O) model. Structured hexahedral mesh was used in the majority of the body with the exception of abdomen. The number of contacts implemented in the model was minimized via node-to-node connections and element property assignment based on the underlying CAD data. Ultimately, the F05-O model consisted of 981 parts, 2.6 million elements, 1.4 million nodes, and had a mass of 51.1 kg.

As there is relatively little biomechanical data specific to anthropometries beyond the average male, small female model responses often require numerical transformation prior to validation. Therefore, a study was conducted utilizing volumetrically scaled human body models to quantitatively compare scaling techniques. This study found that no single technique was ideal for all impact scenarios. However, scaling based on a ratio of effective masses was found to be the most proficient at scaling a reference response to the target. An additional study utilizing human body models was also performed to evaluate the CORA and ISO/TS 18571 objective evaluation techniques. Significant differences were found for the interpretation of these methods and a survey of subject matter experts suggests using the magnitude method in CORA and the ISO shape and phase methods may be the most intuitive approach to reporting objective ratings.

For full body validation, the model was simulated in 10 validation cases ranging from hub impacts to full body sled cases. In order to make comparisons to experimental data, which represent the mass of an average male, the model was compared to experimental corridors using two methods:​ 1) post-hoc scaling the outputs from the baseline F05-O model using the technique applied to the experimental dataset and 2) geometrically morphing the model to the body habitus of the average male to allow direct comparisons. This second step required running the morphed full body model in all 10 simulations for a total of 20 full body simulations. Overall, geometrically morphing the model was found to more closely match the target data with an average ISO score for the rigid impacts of 0.76 compared to 0.67 for the scaled responses. Based on these data, the morphed model was then used for model validation in the vehicle sled cases and attained an average weighted score of 0.69 for the two sled impacts.

The F05-O model was found to be robust and showed fair to good agreement with experimental biomechanical response data as per the results of ISO objective rating metrics. Based on the findings of this study, it was quantitatively demonstrated that full body morphing can be a more effective means model validation than post-hoc data scaling. As human body modeling is extended to address ever more challenging aspects of injury biomechanics, the GHBMC F05-O model is poised to provide needed insight to the biomechanics of small female occupants.