ABSTRACT
The objective of this work was to develop a reusable, rate-sensitive dummy abdomen with abdominal injury assessment capability. The primary goal for the abdomen developed was to have good biofidelity in a variety of loading situations that might be encountered in an automotive collision. This paper presents a review of previous designs for crash dummy abdomens, a description of the development of the new abdomen, results of testing with the new abdomen and instrumentation, and suggestions for future work. The biomechanical response targets for the new abdomen were determined from tests of the mid abdomen done in a companion biomechanical study. The response of the abdominal insert is an aggregate response of the dummy's entire abdominal area and does not address differences in upper versus lower abdominal response, solid versus hollow organs, or organ position or mobility. While the abdomen developed has demonstrated good biofidelity in rigid bar, seat belt and airbag loading situations, some work remains to be done before it can be used in crash testing.
ABSTRACT
A comparison of the Q3 and Hybrid III 3-year-old crash test dummies is presented in this paper. The performance of the dummies were compared in sixty biofidelity tests, seventy-seven static out-of-position airbag tests and sixty-three calibration tests. Various time histories and other data pertaining to accelerations, deflections, forces and moments are compared. In addition, the ease of positioning, handling, and the durability of the dummies in various out-of-position test configurations was assessed. Both the Q3 and Hybrid III 3-year-old dummies were calibrated to their respective specifications. The Hybrid III 3-year-old met its calibration requirements, while the Q3 did not always meet its own calibration requirements. The calibration specifications of the Q3 dummy need to be re-examined and possibly refined. The biofidelity of the Q3 and Hybrid III 3-year-old dummies were evaluated in both frontal and lateral test modes. Each dummy was evaluated against its own and the other's specified requirements, when possible. In the frontal test mode, the Hybrid III 3-year-old acceptably met all of its requirements. The Q3 dummy did not meet all of its own frontal biofidelity requirements. Based on these results, the Hybrid III 3-year-old is more biofidelic for primarily frontal loading conditions. With respect to the lateral biofidelity specifications, neither the Hybrid III 3-year-old nor the Q3 dummy met the requirements for the thorax and pelvis tests performed. Both dummies met the head drop requirements. Neither dummy is recommended for lateral loading conditions. For lateral testing where only the head is impacted, the Hybrid III 3-year-old could be used. In general, the responses of both dummies were repeatable in both the frontal and lateral biofidelity tests performed. The Hybrid III 3-year-old and the Q3 dummies were evaluated in static out-of-position airbag tests with three different side airbag systems (two seat-mounted and one door-mounted system), and one frontal passenger airbag system. Throughout this testing, the Q3 resultant head accelerations exhibited an excessive amount of high-frequency noise causing this dummy to be unacceptable for static out-of-position airbag testing. No significant issues were found with the Hybrid III 3-yearold. It was also determined that the Q3 dummy was more difficult to position repeatedly than the Hybrid III 3-yearold. This was due to the dummy's construction and its lack of rigid landmarks.
ABSTRACT
Biomechanical properties of the six major lumbar spine ligaments were determined from 38 fresh human cadaveric subjects for direct incorporation into mathematical and finite element models. Anterior and posterior longitudinal ligaments, joint capsules, ligamentum flavum, interspinous, and supraspinous ligaments were evaluated. Using the results from in situ isolation tests, individual force-deflection responses from 132 samples were transformed with a normalization procedure into mean force-deflection properties to describe the nonlinear characteristics. Ligament responses based on the mechanical characteristics as well as anatomical considerations, were grouped into T12-L2, L2-L4, and L4-S1 levels maintaining individuality and nonlinearity. A total of 18 data curves are presented. Geometrical measurements of original length and cross-sectional area for these six major ligaments were determined using cryomicrotomy techniques. Derived parameters including failure stress and strain were computed using the strength and geometry information. These properties for the lumbar spinal ligaments which are based on identical definitions used in mechanical testing and geometrical assay will permit more realistic and consistent inputs for analytical models.
