Guardrail terminals have evolved to the point where they absorb energy while utilizing tension in the rail to countermand the compression. However, non-gating terminals have yet to be developed. In the present study, the possibility of a non-gating guardrail terminal was investigated. Specifically, the combination of lateral and longitudinal forces that produce non-gating performance were determined from computer simulation. Next, a prototype terminal was crash tested at the research team’s laboratory. A terminal head was designed to deform the guardrail, and its internal structure was adjustable to control the longitudinal force. Posts were designed to control lateral forces by modifying their section modulus. This controlled the force at which the posts buckled in response to a collision. A prototype was subjected to two 15° crash tests using an SUV and a small car. In both tests, the kinetic energy of the test vehicle was fully absorbed and the Manual for Assessing Safety Hardware (MASH) criteria would have been met. Neither vehicle passed beyond the terminal head, making these test results the first of their kind.

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Recently Kerley has developed a soil model suitable for implementation in Eulerian hydrocodes. The model has been installed into CTH [1]. While basic features of the model suggest it may be suitable for modeling ground shock and cratering problems, it has not been extensively validated. As such, in order to provide more confidence in the use the model, a series of calculations was conducted to compare Kerley’s model to the Hybrid Elastic-Plastic (HEP) model.

In order to make the process of material model development more systematic for energetic materials, we have developed a procedure that makes use of nonlinear optimization to derive optimal values of parameters in the material models. A framework has been developed that makes use of the optimization software package DAKOTA driving the hydrocode CTH (both CTH and DAKOTA are developed and maintained at Sandia National Laboratories). CTH was used to model a set of characterization experiments that were used as the basis for the calibration of a particular model; for example, the cylinder test was used to calibrate the JWL equation of state, and the wedge test for the HVRB reactive burn model. As a verification test of the framework, we have determined material model constants for TNT and compared them to values published in the literature.