Assessment of composite foam-insulated concrete sandwich panels under low-velocity impact

With the increasing application of composite materials in civil engineering, it important to thoroughly understand the performance of multilayer sandwich structures under impact loading. Nowadays, sandwich panels made of concrete face sheets bonded to foam cores through shear connectors, have gained widespread applications in civil engineering projects. Until now, research on such structures has often been limited to static analyses, and it is necessary to investigate their behaviour under dynamic loading. In this research, the effect of dynamic impact loading on the mentioned structures has been studied. Three-dimensional finite element modelling, along with the explicit dynamic analysis, has been used to achieve this objective. First, the accuracy of numerical results is evaluated through comparison with the available experimental results. Then, the effects of various parameters, such as the concrete strength of face-sheets, shear strength of connectors between the layers, the amount of reinforcements embedded in the concrete layers, and the effect of the speed of the impactor, were investigated. The results show that by increasing the impact speed, the rate of penetration and indentation in the host sandwich panel also increase. Also, with increasing the concrete strength, the penetration of the projectile and the indentation decrease. By preventing the slippage between the layers, the resistance of the composite sandwich panel against the impact loads is significantly increased. Increasing the amount of reinforcement also increases and improves the impact resistance of the sandwich panel.