Effect of Strain Rates on the Compressive Response of Neck Rubber From Humanetics HIII 50th Percentile Male Dummy Under Different Loading Sequences

Abstract

Abstract : Anthropomorphic test dummies (ATDs) are used to understand the response of humans exposed to different possible extreme loading scenarios encountered as occupants of automotives, aircraft, and military vehicles. The Warrior Injury Assessment Manikin (WIAMan) program has been established by the U.S. Army to create a higher fidelity ATD that will be used to assess severity of injury to humans in blast and high accelerative loading situations, where loading rates could be higher than during the standard automotive crash tests. Simulation of these extreme events to extract the accurate response of ATDs requires incorporating the constitutive response of the materials used in the ATDs under different loading rates. To build constitutive models for numerical codes for WIAMan, the materials used in ATDs must be investigated to discover how the materials behave at various loading rates. In this study, the rate-dependent behavior of neck rubber used in the Hybrid III, an automotive ATD, was investigated over quasi-static (0.001 s-1), intermediate (1 s-1), and high (500 s-1, 1300 s-1, and 2300 s-1) strain rates. The stress relaxation behavior at quasi-static and intermediate rates was also studied. In addition, storage and loss moduli of the rubber were also obtained as a function of frequency and temperature. These various types of loading under different rates were used to evaluate the various representations of constitutive models in literature. The Bergstrom-Boyce model was identified as the model that best represents the experimental data.