Nuclear weaponsBlast tube tests at Sandia simulate shock wave conditions nuclear weapons could face
Sandia National Lab researchers are using a blast tube configurable to 120 feet to demonstrate how well nuclear weapons could survive the shock wave of a blast from an enemy weapon and to help validate the modeling.
You can learn a lot from a blast tube. You can learn more when you couple blast experiments with computer modeling.
Sandia National Laboratories researchers are using a blast tube configurable to 120 feet to demonstrate how well nuclear weapons could survive the shock wave of a blast from an enemy weapon and to help validate the modeling.
Sandia recently completed a two-year series of blast tube tests for one nuclear weapon program and started tests for another. Each series requires instrumentation, explosives, high-speed cameras and computer modeling.
Tests simulate part of the environment a weapon re-entering the Earth’s atmosphere would face if another nuclear weapon went off nearby, said test director Nathan Glenn.
Each series starts with calibration shots that allow team members to verify blast wave parameters and at the same time validate the computer model. The team hangs an explosive charge at one end of the 6-foot diameter tube and places pressure transducers along its length. Transducers sense the strength of the blast pressure moving through the tube — higher pressure closer to the charge, falling off farther away.
Modeler Greg Tipton, who helped design the series, said tests validate the computer models of the structural dynamics of the system. “We can then use the models to simulate real environments we can’t actually test to,” he said.
Figuring out how to conduct testing
It’s complex just to analyze how to conduct a test, Tipton said. The pressure drives how big a charge is needed and how the test article is positioned in the tube, and that determines the loading, or the amount of force applied to the test unit. In turn, the loading determines the structural response of the test article. “So, the team does end-to-end calculations to simulate the explosive going off, the shock wave through the tube, the shock propagation over the test unit and then the structural response to the shock wave. All of that data is used to determine the right orientation, the right shock level, to validate the models,” Tipton said.
