| Summary: | 碩士 === 國立臺灣大學 === 工程科學及海洋工程學研究所 === 99 === In this study, numerical simulation methods to analysis the dynamic response of concrete subjected to penetration of high speed projectile. The effects of large strain, high strain rate and high pressure on the dynamic behavior have been investigated. The LS-DYNA finite element analysis software was used for numerical simulation, and the characteristic of two different models of concrete materials: Mat_Johnson_Holmquist_Concrete and Mat_Soil_Concrete were compared.
First, a reasonable numerical model was examined through three parameters: the effects of element size on the convergence of analysis result, a reasonable size parameter λ(projectile radius/mesh size) was summarized. The effect of time step size(t) and penalty stiffness factor(f_s) on the differences of numerical results have been discussed. Numerical analysis for Hanchak’s experiments was carried out, the results were compared with experiment results to verify the reliability of numerical models. The numerical model was above compared to empricial formula to predict the penetration depth to display the characteristic of concrete structure. Finally, we summarized the concrete’s failure model during the process of projectile penetration concrete target.
Finally, the difference of anti-penetration properties between the single concrete target and multiple concrete targets were investigated. The results show that the proposed numerical model can predict effectively the dynamic response and failure conditions under consideration of large strain, high strain rate and high pressure situations
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