Leveraging HyperWorks for Advanced Human Body Models in Vehicle Crash Simulations

Wake Forest Baptist Medical Center is a leading research university in biomedical sciences and bioengineering. The Center of Injury Biomechanics (CIB) in the School of Medicine at Wake Forest Baptist investigates injury mechanisms following trauma resulting from vehicle crash to develop a greater understanding of human tolerance to injury and to engineer enhanced safety countermeasures. Since 2006, Drs. Joel Stitzel and Scott Gayzik of the CIB have been principle investigators for the Global Human Body Modeling Consortium(GHBMC), an international consortium of automakers and suppliers working with research universities and government agencies to advance human body modeling technologies for crash simulation.

Wake Forest Baptist Medical Center, a leading research university in biomedical sciences and bioengineering, was tasked with developing highly detailed, finite-element human body models for vehicle crash simulation. The Center of Injury Biomechanics (CIB) at the university was to investigate injury mechanisms following trauma resulting from vehicle crashes to develop a greater understanding of human tolerance to injury and to engineer enhanced safety countermeasures. The challenge was to mathematically quantify fundamental human body organs, skeletal members, and body extremities that are subject to trauma. The resulting medical image data had to accurately represent a range of vehicle occupants: adults (male & female), children (3-6 years old), and infants. The human body data then had to be discretized to generate accurate finite element (FE) models of the varied human body systems. These models then had to be integrated to formulate a model of the entire human body, which then had to be validated in vehicle crashworthiness simulations with occupant and pedestrian impact conditions.

The Global Human Body Modeling Consortium (GHBMC) applied Altair HyperMesh and its HyperMorph module to develop detailed finite element models based on extensive scanned data of human body organs, tissues, and skeletal systems. The data was developed under the direction of established GHBMC Centers of Expertise (COE) at selected universities. Each of these Centers had responsibility for CAD and finite element modeling of specific regions of the human body. An additional COE was established to integrate data and finite element models from each subsystem into a full body model. The GHBMC selected the Wake Forest University CIB to complete the extensive integration work required for the Total Human Body COE. Altair made available the entire HyperWorks suite of CAE tools to enable the finite element and crashworthiness analysis-related work for each COE. HyperMesh was applied for finite element modeling of human body CAD data, while RADIOSS was applied for vehicle crash simulation validation. The Wake Forest Baptist team also developed a modeling scaling approach to rapidly develop other sized models, leveraging the large amount of existing data for the M50 development, including external anthropometry and medical imaging data.

• The use of HyperWorks tools for finite element model development and validation has proven to be a significant advancement in the field of injury biomechanics and trauma research. The detailed mathematical modeling of the human body has enabled computational analysis of real-world injury scenarios, allowing for engineering improvements to help prevent potential human injury. The development of the M50 model, in particular, has been a significant achievement, with the model being validated for 38% of all crash-induced injuries. The development of reduced-size models has also increased simulation efficiency, enabling faster run times and rapid kinematic evaluation of an impact event. The success of this project has paved the way for future efforts to develop simplified and detailed full-body models for male 5th and 95th percentile size, as well as corresponding models for female 5th, 50th, and 95th percentile size.

• A 50th percentile male vehicle occupant (M50) model has been developed that consists of 2.2 million elements, 1.3 million nodes, and weighs 76.9 kg.
• The GHBMC M50 model has been validated for 38% of all crash-induced injuries.
• The model is detailed enough for simulating 80% of all crash-induced injuries.