Investigation of Explosively Driven Fragmentation of Metals - Two Dimensional Fracture and Fragmentation of Metal Shells: Progress Report II

Grady, D

Lawrence Livermore National Laboratory

关键词: Fragmentation;    Fractures;    Detonation Waves;    Transients;    Chemical Explosives;   

DOI  :  10.2172/15005042
RP-ID  :  UCRL-CR-152264
RP-ID  :  W-7405-ENG-48
RP-ID  :  15005042

美国|英语

来源: UNT Digital Library

【 摘 要 】

High explosive enclosed by a metal case qualitatively describes an essential component of high energy systems of importance to the Department of Energy. Detonation of the high explosive causes intense transient pressure loading of the metal following arrival of normal or obliquely incident explosive detonation wave. Subsequent expansion and deformation of the metal case leads to eventual rupture and the opening of fractures and fissures. Details of the rupture process are critical to performance of the system. Consequently, it is essential that the material and kinematic issues governing the processes of dynamic loading and subsequent failure of an explosive-metal case component within a functioning system be adequately understood. Among the reasons are to quantify existing performance, characterize potential degradation of performance resulting from system aging, and optimizing or maintaining system performance through implementation of structural or material changes. The physical and engineering issues underlying this dynamic response and failure phenomena are not adequately understood. The purpose of the present program is to identify the key issues and develop theoretical, computational and experimental models needed to achieve a satisfactory theoretical and analysis framework for analysis of metal case failure in the explosive environment. Specific tasks within the present program include: (1) Models and theories currently being pursued based on physical principles of both the statistical fragmentation concepts of Mott and the energy-based concept of others show promise of providing the analytic and computational methodology capable of predicting explosion-induced fracture and fragmentation of metal components. Experimental studies initiated in the earlier effort offer promise to provide critical test data for validation. The present task shall involve the further refinement and development of the dynamic failure and fragmentation models and theories, and the concomitant application and validation of these models and theories to experimental test data with the focus of providing the analytic methodology sought in the programmatic effort. (2) Stand-alone engineering algorithms and large-scale computer codes will constitute the calculational methodology developed to simulate and analyze the operational system response of metal components in explosive-loading environments. This task will pursue the preparation and implementation of the models and theories of dynamic fragmentation above to the status of engineering and computational analysis tools. The engineering and computer analysis tools pursued will also be tested against experimental fracture and fragmentation data emerging from the program effort.