Dynamic analysis of non-homogeneous concrete blocks mixed by SiO2 nanoparticles subjected to blast load experimentally and theoretically

Abstract

In this paper, dynamic analysis of non-homogenous concrete block resting on soil foundation subjected to blast load is presented experimentally and theoretically. The non-homogenous concrete block is made from two concrete blocks filled by barite. The concrete blocks are reinforced by SiO2 nanoparticles where the Mori-Tanaka model is used for calculating the effective material properties of the structure. The soil medium is simulated by spring constant of Winkler medium. Based on Mindlin theory, energy method and Hamilton's principle, the motion equations are derived. The transferred weighting differential quadrature method (TW-DQM) is used for solution of the theoretical model. In addition, the experimental tests are done for obtaining the maximum velocity of the structure in vertical, radial and tangential directions. Comparison of experimental tests and theoretical model are close to each other which show the accuracy of the mathematical modeling. The effects of different parameters such as volume percent of SiO2 nanoparticles, agglomeration of SiO2 nanoparticles, soil medium, length and width of the structure, discontinues distance and the slope discontinuity are shown on the maximum velocity of the structure. The results show that increasing the discontinues distance higher than 40 cm, the vertical maximum velocity dose not any significant changes. It can be concluded that the slope discontinuity of 45 degree is an optimum value. With comparing the result of Geophone 1 (before discontinuity) and Geophone 3 (after discontinuity), it can be concluded that the wave speed will be reduced about 230% which can improve the safety of the structure.