Abstract Reinforced concrete structures may suffer some accidental loadings, such as fire, impact(or blast), etc.To study the effects of high temperature and impact on the performance of RC slabs,a three-dimensional simulation model was established in the present work. A two-step analysis methodwas utilized to consider the combined effect of fire and impact loadings. Namely, the thermal conduction behavior of the concrete slab was simulated firstly, and then, the “result output”ofthe temperature field was used as the “initial condition” to simulate the impact behavior ofRC slabs. On the basis of verifying the rationality of the three-dimensional simulation model, the influence of fire exposure time on the impact performance of RC slabs was analyzed. The difference of impactperformances between RC slabs under high-temperature exposure and after cooling downwas discussed. Thus, the failure mode and failure mechanism of the RC slabswere revealed. The simulation results showed that the impact performance of RC slabs subjected to fire and cooling down, in terms of failure pattern, overall deformation, energy dissipation, responses of impact and reaction force as well as acceleration, is better than that under high-temperature exposure, but still worse than that at room temperature.This difference becomes larger with respect to fire duration. As the fire duration increases, the residual bearing capacity and natural frequency which reflects the overall stiffness of the RC slab decrease, but the displacement and energy dissipation increase.

中文翻译：

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高温对钢筋混凝土板低速冲击性能的影响

摘要 钢筋混凝土结构可能会承受火灾、冲击（或爆炸）等意外载荷。为了研究高温和冲击对钢筋混凝土板性能的影响，本文建立了三维仿真模型。 . 采用两步分析方法来考虑火灾和冲击载荷的综合影响。即先模拟混凝土板的热传导行为，然后以温度场的“结果输出”为“初始条件”，模拟RC板的冲击行为。在验证三维仿真模型合理性的基础上，分析了火灾暴露时间对钢筋混凝土板冲击性能的影响。讨论了高温暴露和冷却后RC板之间冲击性能的差异。从而揭示了钢筋混凝土板的失效模式和失效机制。仿真结果表明，RC板在火灾和冷却后的冲击性能，在破坏模式、整体变形、能量耗散、冲击和反作用力响应以及加速度方面均优于高温暴露下的RC板。 ，但仍然比室温下的差。这种差异随着火灾持续时间而变得更大。随着火灾持续时间的增加，反映钢筋混凝土板整体刚度的残余承载力和固有频率降低，但位移和耗能增加。揭示了钢筋混凝土板的失效模式和失效机理。仿真结果表明，RC板在火灾和冷却后的冲击性能，在破坏模式、整体变形、能量耗散、冲击和反作用力响应以及加速度方面均优于高温暴露下的RC板。 ，但仍然比室温下的差。这种差异随着火灾持续时间而变得更大。随着火灾持续时间的增加，反映钢筋混凝土板整体刚度的残余承载力和固有频率降低，但位移和耗能增加。揭示了钢筋混凝土板的失效模式和失效机理。仿真结果表明，RC板在火灾和冷却后的冲击性能，在破坏模式、整体变形、能量耗散、冲击和反作用力响应以及加速度方面均优于高温暴露下的RC板。 ，但仍然比室温下的差。这种差异随着火灾持续时间而变得更大。随着火灾持续时间的增加，反映钢筋混凝土板整体刚度的残余承载力和固有频率降低，但位移和耗能增加。整体变形、能量耗散、冲击和反作用力响应以及加速度，优于高温暴露，但仍比室温差。这种差异随着火灾持续时间而变大。随着火灾持续时间的增加，反映钢筋混凝土板整体刚度的残余承载力和固有频率降低，但位移和耗能增加。整体变形、能量耗散、冲击和反作用力响应以及加速度，优于高温暴露，但仍比室温差。这种差异随着火灾持续时间而变大。随着火灾持续时间的增加，反映钢筋混凝土板整体刚度的残余承载力和固有频率降低，但位移和耗能增加。