A building can be subject to multiple accidental loads during its service life. Partially precast concrete (PC) beams are primary force-bearing members. When subjected to an impact load, their impact resistance considerably affects the overall safety of the structure. In this study, we performed numerical analyses of the dynamic response of PC beams subjected to impact loading. The related parameters, including the element type, material model, contact type, and hourglass control, were discussed in detail. The simulation and test results were compared. The model's validity is verified from four aspects: energy conversion, failure form, impact-force time history curve, and midspan-displacement time history curve. Based on these findings, the effects of the concrete strength, longitudinal reinforcement ratio, and stirrup ratio on the impact resistance of the components were evaluated. Furthermore, the differences in the equivalent plastic strain cloud diagram, impact-force time history curve, and midspan-displacement time history curve under different parameters were compared. The results show that an increase in the strength of the post-pouring concrete can reduce local damage to PC beams, and improving the overall strength of concrete can reduce overall damage of PC beams. In addition, an increase in the longitudinal reinforcement ratio can ease the failure of the normal cross-section of PC beams, and an increase in the stirrup ratio can effectively inhibit the generation and development of oblique cracks. Then, by fitting the parameters, we established simplified formulas for calculating the peak and residual values of the midspan displacement. According to the formulas, when the external impact mass and height are known, the component's damage degree can then be predicted, which provides a basis for the design of fabricated structures.
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