PSI - Issue 51

R. Andreotti et al. / Procedia Structural Integrity 51 (2023) 37–43 R. Andreotti et al. / Structural Integrity Procedia 00 (2023) 000–000

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Fig. 11. Comparison between the resultant reaction forces [N] in the direction of the impact. Fluid structure interaction (red), uniform pressure distribution on a circular area with 1.5 times the radius of the bullet (green), uniform pressure distribution on a circular area with 2.0 times the radius of the bullet (blue). 5. Conclusions All the results show that the proposed simplified methods allow a representative and consistent prediction of the load history due to bullet splash. The consistency of the deformation field and stress field at distances above 10mm from the epicenter suggests the effectiveness of the load history method for the proposed aim of allowing large-scale assessment of protective structural systems by means of parsimonious finite element simulations. Ongoing developments involve the application of the methods to a larger set of bullet-target interactions as well as the analysis of the influence of partial fragmentation on the effective load history, to discover a possible criterion to overcome the strict bullet-splash hypothesis, therefore finding a general parsimonious approach for efficient structural assessment of ballistic protection systems. Acknowledgements Riccardo Andreotti and Mauro Quercia were responsible for all the calculation activities. Andrea Casaroli was responsible for the experimental activities. Marco Boniardi leads the project. References Andreotti, R., Abate, S., Casaroli, A., Quercia, M., Fossati, R., Boniardi, M. V., 2021. A simplified ale model for finite element simulation of ballistic impacts with bullet splash – development and experimental validation. Frattura ed Integrità Strutturale 15(57), 223–245. Andreotti, R., Casaroli, A., Quercia, M., Boniardi, M. V., 2022. A simplified formula to estimate the load history due to ballistic impacts with bullet splash. Development and validation for finite element simulation of 9x21mm full metal jacket bullets. Frattura ed Integrità Strutturale 16(62), 602–612. Boyce, B. L., Crenshaw, T.B., Dilmore, M. F., 2007. The Strain-Rate Sensitivity of High- Strength High-Toughness Steels, Albuquerque, New Mexico 87185 and Livermore, California 94550.

LSTC, 2015. LS-DYNA R8.0 Keyword User’s Manual – Volume I. LSTC, 2015. LS-DYNA R8.0 Keyword User’s Manual – Volume II.