Annette L. Irwin

Biomechanical basis for the CRABI and Hybrid III child dummies

A family of adult and child size dummies was developed under the direction of two task groups of the SAE Mechanical Human Simulation Subcommittee of the Human Biomechanics and Simulation Standards Committee. These new child size dummies represent fiftieth percentile children who are 6 months, 12 months, 18 months, 3 years, and 6 years old. The sizes and total body weights of the dummies were based on detailed anthropometry studies of children of these ages. The techniques used to establish the segment masses and the resulting design goals are detailed. Appropriate impact response requirements were scaled from the biofidelity response requirements of the Hybrid III, taking into account the differences in size, mass and elastic modulus of bone between adults and children. The techniques used to establish the biomechanical impact response requirements for the child dummies are discussed and the resulting biomechanical impact response requirements are given.

Injury Risk Curves for Children and Adults in Frontal and Rear Collisions

This paper describes the development of injury risk curves for measurements made with the CRABI and Hybrid III family of biofidelic child and adult dummies that are used to evaluate restraint systems in frontal and rear-end collision simulations. Injury tolerance data are normalized for size and strength considerations. These data are analyzed to give normalized injury risk curves for neck tension, neck extension moment, combined neck tension and extension moment, sternal compression, the rate of sternal compression, and the rate of abdominal compression for children and adults. Using these injury risk curves dummy response limits can be defined for prescribed injury risk levels. The injury risk levels associated with the various injury assessment reference values currently used with the CRABI and Hybrid III family of dummies are noted.

TECHNICAL SPECIFICATIONS OF THE SID-IIS DUMMY

A new dummy, the SID-IIs, a small (s) second generation (II) side impact dummy (SID) is reported. The SID-IIs is being developed to: 1) help evaluate proposed side impact countermeasures, such as side airbags, for the smaller segment of the population. This smaller segment includes both children and small adults; 2) help harmonize between existing side impact dummies toward one design worldwide by offering the begining of a family of biofidelic Anthropomorphic Test Devices (ATD) with as much worldwide input as possible. The dummy weighs 43.5 kg, is 790 mm high and has over 100 data channels available.

Anthropomorphic Test Devices and Injury Risk Assessments

Anthropomorphic test devices (ATDs), commonly referred to as dummies, are mechanical surrogates of the human that are used by the automotive industry to evaluate the occupant protection potential of various types of restraint systems in simulated collisions of new vehicle designs. Dummies are classified according to size, age, sex and impact direction. There are adult male and female dummies of different sizes, and child dummies that represent different ages. These dummies are used to assess occupant protection in frontal, side, rear and rollover collision simulations. The midsize adult male dummy is the most utilized size in automotive restraint testing. It approximates the median height and weight of the 50th percentile adult male population. The heights and weights of the small female and large male adult dummies are approximately those of the 5th percentile female and the 95th percentile male, respectively. The adult dummies are referred to as small female, midsize male and large male to avoid debates about whether the dimensions are consistent with the latest published percentile classifications. Child dummies have the median heights and weights of children of the specific age groups that they represent without regard to sex. They are referred to by age.

Brain injury risk assessment of frontal crash test results

An objective, biomechanically based assessment is made of the risks of life-threatening brain injury of frontal crash test results. Published 15 ms HIC values for driver and right front passenger dummies of frontal barrier crash tests conducted by Transport Canada and NHTSA are analyzed using the brain injury risk curve of Prasad and Mertz. Ninety-four percent of the occupants involved in the 30 mph, frontal barrier compliance tests had risks of life-threatening brain injury less than 5 percent. Only 3 percent had risks greater than 16 percent which correpsonds to 15 ms HIC > 1000. For belt restrained occupants without head contact with the interior, the risks of life- threatening brain injury were less than 2 percent. In contrast, for the more severe NCAP test condition, 27 percent of the drivers and 21 percent of the passengers had life-threatening brain injury risks greater than 16 percent. However, for belt/air bag restrained occupants the brain injury risks were less than 7 percent. (A) For the covering abstract see IRRD 874898.

Using a hybrid III anthropomorphic test device with back constraint to evaluate robot impact to the chest

Impact tests using an Anthropomorphic Test Device (ATD) or a dummy were conducted to assess the risk that a moving mass, such as a robot, might pose to an individual against a stationary constraint. A mathematic model was also used to simulate the dummys responses to impacts from different combinations of mass and velocity. The results showed that the sternum-to-spine deflection, or chest compression, was higher when the dummys back was constrained than when it was unconstrained. A study plan for understanding the risk from a moving mass such as a robot was proposed.