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This paper aims to provide a numerical model able to represent the behavior of reinforced concrete slabs subjected to impact loads. The nonlinear finite element analysis adopted by ABAQUS/Explicit Software was used in this study. A parametric study was conducted to provide a comprehensive understanding of the behavior of reinforced concrete slabs subjected to impact load. Two parameters were varied amongst the slabs which classified in to two groups. In the first groups, the thickness of slabs is variable, which was equal to (75, 100, 150 mm). In the second group, the thickness of the slab is constant and the variable was the reinforcement ratio, which ranged from (0.58 to 1%), per layer. In dynamic analysis, the load-time history and deflection-time relation were investigated. For the first group, obviously, as the slab thickness increased, the maximum central deflection of the slabs decreased by (48 – 84 %). Also, the impact force of the slabs increased by (40 – 106%) as the thickness of the slab increased by (33 – 100%). For the second group, the maximum central deflection of the slabs decreased by (6.6 – 8.8 %) as the steel reinforcement increased by (0.58 – 1 %). It was observed in the second group that the change in the value of the impact force was very limited. This lead to a fact that the impact force was not affected by the change of the reinforcement ratio, but mainly affected by the change of the slab thickness.

Numerical models for impact load assessment are becoming increasingly reliable and accurate in recent years. The processing time duration for such analysis has been decreased to an acceptable level when combined with modern computer hardware. The aim of this study was to represent a simulation technique and to verify the validity of modern software in measuring the response of reinforced concrete beam strengthened by carbon fiber-reinforced polymer (CFRP) sheet subjected to impact loads at the ultimate load ranges. In this investigation, ABAQUS/Explicit Software’s nonlinear finite element modeling had been used. The response of the impact force–time history and the displacement–time history graphs were compared to the existing experimental results. The adopted general-purpose finite element analysis is verified to be capable of simulating and accurately forecasting the impact behavior for structural systems. In addition, a parametric analysis was carried out to gain a better knowledge of the performance of reinforced concrete beams under impact loading. Four parameters had been changed among the analyzed beams such as impact velocity, impact mass, CFRP sheet thickness, and compressive strength of concrete. Generally, it has been found that using a CFRP sheet in strengthening reinforced concrete beams can greatly improve the members’ impact behavior by improving stiffness as well as increasing load-carrying capacities. The enhanced performance characteristics of strengthening beams under impact loads correlate with the applied kinetic energy and CFRP thicknesses. Finally, for beams with high compressive strength, the deflection values were reduced because of the increase in stiffness.

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This paper examines a progression of experimental studies designed to investigate the response of reinforced concrete slabs subjected to static and high-mass low-velocity impact loads. A total of ten reinforced concrete slabs were tested: three specimens were tested under static load by loading the specimens at their mid-point, and seven specimens were tested under impact load to research the high-mass, low-velocity impact behaviours of reinforced concrete slabs using a drop-weight facility. Measurements methods included a load cell, acceleration, strain in the reinforcement steel and a laser sensor to measure deflection in the centre and various quarters of the slabs (LVDT). The experimental variables included in this study focused mainly on the thickness of slab under static and impact loads, the mass of the striking object, and the height of the striking object for impact loads. The results showed that under static loads, the mean of the thickness of the slab increased by 33 to 100%, the maximum deflection at the central point decreased by 45 to 63 %, and the load capacity of the slabs increased by 77 to 265%. With respect to high-mass low-velocity impact loads, as the slab thickness increase by 33to 100%, the maximum deflection at the centre of the slabs decreased by 47.7 to 84 % and the impact force increased by 37.5 to 102%. When the height of the striking object was increased by 33 to 66%, the maximum central deflection of the slabs also increased by 24 to 72.3%, and the impact loads increased by 11 to 23.3%. Increases in the mass of the striking object by 50 to 100% led to the maximum central deflection of the slabs increasing by about 54 to 122% and to the impact loads increasing by 13 to 18.6%.