The lack of clear guidelines for the design of structural members against unforeseen loads, such as impact and explosion, inspired researchers to fill this knowledge gap. The key focus of the current study is to investigate the flexural strength of composite beams under high strain rate, a widely utilized structural element in multi-story buildings and bridges. The Abaqus software was utilized to construct finite element models, which were then validated by comparing them to previously published laboratory findings. Subsequently, an extensive investigation was conducted to explore the specific parameters that notably affect the behavior of composite members, including slab thickness, concrete compressive strength, and impact velocity. The results from both the FE and experimental tests were closely aligned, exhibiting similar force and displacement patterns proving the numerical model's accuracy and reliability. The addition of a concrete slab significantly improved its ability to withstand impact by 50%. Also, this enhancement increases as the thickness of the slab rises. Finally, the response of the composite beam under high-strain loading is greatly affected by the impact velocity. In simpler terms, a decrease of approximately 20% in displacement was observed. Despite this, it was noted that there was only a slight 10% rise in internal moment with increasing velocity.