Abstract
As a complex process, an underwater explosion is affected by different factors. Shock factors are variables used to characterize the severity of a shock based on scaling laws, which are conventionally used to designate the effect of an underwater explosion on a target. To reveal the mechanism involved in the dynamic response of an air-backed plate induced by underwater explosion, this study established a new shock factor to explain the dynamic mechanism of an underwater explosion. The shock factor was defined as the total energy impacting a structure that is subjected to a spherical wave. To validate the effectiveness of the shock factor, both numerical and centrifugal modeling were adopted. The numerical results indicate that changes in the standoff distances, defined as the distance between explosives and the upstream surface of a structure, and the eccentric distances, defined as the distance between explosives and the centroid of the structure wet surface, have almost no influence on the strain energy, kinetic energy, or total energy of the air-backed plate, at constant shock factor. Then the centrifugal test results were used to assess the dynamic responses under different explosive weights, standoff distances, and water depths. The results show that both near- and far-field underwater explosions were effectively assessed using shock factors. The shock factor with clear physical significance unifies the effects of explosive weight, explosive position, and structure dimension. The shock environment could be simply evaluated by the shock factor when subjected to an underwater explosion, which could also be useful in designing model tests based on scaling laws.
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Data Availability Statement
Some or all data and models that support the findings of this study are available from the corresponding author upon reasonable request (numerical models for validation of the shock factors).
Acknowledgments
This study was supported by the National Natural Science Foundation of China (Grant Nos. 51879283 and 51339006).
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Published In
Journal of Structural Engineering
Volume 146 • Issue 10 • October 2020
Copyright
© 2020 American Society of Civil Engineers.
History
Received: Nov 22, 2018
Accepted: May 4, 2020
Published online: Jul 29, 2020
Published in print: Oct 1, 2020
Discussion open until: Dec 29, 2020
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