增幅冲击下钢筋混凝土板的抗冲击性能

钢筋混凝土板在服役期间可能承受落物多角度连续撞击等多次冲击荷载作用，钢筋混凝土板抵抗多次冲击的能力、多次冲击作用下钢筋混凝土板的性能演化和剩余性能评估等问题至关重要，其中，多次冲击的加载制度是研究钢筋混凝土板抗冲击性能的重点。为研究多次冲击下钢筋混凝土板的抗冲击性能，利用落锤和摆锤试验研究钢筋混凝土板在增幅冲击下的抗冲击性能，获得钢筋混凝土板在历次冲击过程中的冲击力时程曲线以及历次冲击后的整体变形和凹陷变形特征，分析钢筋混凝土板的吸能特性和累计损伤演化规律，研究钢筋混凝土板受冲击后的残余性能。结果表明：冲击角度对钢筋混凝土板的变形有显著影响，斜向冲击对钢筋混凝土板安全性能的影响更大；增幅冲击降低钢筋混凝土板的吸能能力，提高其破坏率，钢筋混凝土板的冲击响应相对于恒重重复冲击更加稳定。

Impact resistance of reinforced concrete slabs under amplitude impacts

Reinforced concrete slabs during the service period may suffer repeated impacts from falling objects with different impact angle. The capability of reinforced concrete slabs to resist multiple impacts, the performance evolution of reinforced concrete slabs under multiple impacts and the residual performance evaluation are vital to people''s livelihood and safety. Notably, the multiple impact loading system is the key to investigate the impact resistance of reinforced concrete slabs. To study the impact resistance of reinforced concrete slabs under multiple impacts, drop hammer and pendulum impact test was carried out, and the impact performance of reinforced concrete (RC) slabs under amplitude impacts was scrutinized with the cumulative damage characteristics of the RC slabs analyzed, the impact force-time history curves of each impact and the global and the local deformations of the RC slabs after each impact examined. The energy-absorbed capacity and the residual performance of the impacted slab were explored. The experimental results show that the deformation of the RC slabs is affected by the impact angle with the oblique impact producing a greater influence on the safety performance of reinforced concrete slabs. Moreover, the energy-absorbed capacity of the RC slabs is reduced due to the amplitude impact force which causes more damage of the slab. The impact response of the slab under amplitude impacts proves to be more stable than that of the repeated-impact with a constant weight.