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The evolution of microstructure in a Mg 3.4%AI-0.16%Zn-0.33%Mn alloy tube was studied during deformation by ring hoop tension testing (RHTT). When the tests were carried out at moderate temperatures and relatively high strain rates, the accompanying c-axis strains were mainly accommodated by twin formation. At temperatures above 200°C and the lowest strain rate (0.001s-1), the formation of voids in the partially dynamically recrystallized regions caused premature fracture. The microstructural development in hot gasformed samples was similar to that observed during RHTT testing. These results indicate that RHTT testing is an effective way of studying the deformation behavior of Mg alloys during tube gas forming.

Recently there has been a greater awareness of the increased risk of certain injuries associated with air bag deployment, especially the risks to small occupants, often women. These injuries include serious eye and upper extremity injuries and even fatalities. This study investigates the interaction of a deploying air bag with cadaveric upper extremities in a typical driving posture; testing concentrates on female occupants. The goals of this investigation are to determine the risk of upper extremity injury caused by primary contact with a deploying air bag and to elucidate the mechanisms of these upper extremity injuries. Five air bags were used that are representative of a wide range of air bag ‘aggressivities’ in the current automobile fleet. This air bag ‘aggressivity’ was quantified using the response of a dummy forearm under air bag deployment.

Use of ultra high strength steel (UHSS) sheet in automotive components has potential to simultaneously reduce weight and increase crashworthiness. For crashworthiness design and simulation, constitutive equations are required; however, these are scarce for UHSS. Also, UHSS sheets may suffer unexpected fracture such as shear fracture, and toughness data for UHSS sheets is very limited. In this work, effects of strain rate and temperature on flow stress of two UHSS sheet steels (a dual-phase ferritic/martensitic DP980 and a martensitic boron (B) steel) are experimentally investigated and compared to a simple constitutive equation for structural steels based on thermal-activation theory of dislocation motion. The flow stress of the two UHSS steels obeys a constitutive equation similar to that of structural steels of other microstructures (ferrite, ferrite/pearlite, pearlite, ferrite/bainite, and bainite).