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Abstract:
Recent experiments have demonstrated that the current methodologies for predicting loads on buried structures resulting from the nearby detonation of a conventional weapon are not adequate. Errors in predicting the load could lead to significant errors in predicting the response of the structure. In analyses which have been performed in the past to determine the response of structures to conventional weapons, decoupling assumptions were made so that the detonation of the charge in the soil is not included in the calculation. In these analyses assumptions are made which affect the loads applied to the structure. A procedure which did not require these types of assumptions was needed to determine the characteristics of the loads transferred to the structure. This required that the charge, soil, and structure be modeled in the calculation. Based on its user's manual, the finite element program DYNA3D had all of the characterisitics needed to conduct this investigation. After a preliminary review, determined the at DYNA3D was not capable of performing these calculations without extensive modifications. These modifications included the implementations of a new Cap model for the soil. The new model was evaluated for its accuracy in reproducing free-field stresses for clay and sand, and can be used immediately adjacent to the explosive source. Due to large deformations and very high strains and strain rates in the soil near the charge, it wad difficult to maintain the stabiligy of the calculation.
| Limitations: |
APPROVED FOR PUBLIC RELEASE |
| Description: |
Final rept. |
| Pages: |
81 |
| Report Date: |
APR 92 |
| Report Number: |
A563162 |
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