钢筋混凝土柱抗水平冲击行为数值研究

Numerical Investigation on Resistant Behavior of Reinforced Concrete Columns under Horizontal Impact Loading

钢筋混凝土柱作为工程结构的主要竖向承重构件,其在车辆、海啸残骸等水平冲击作用下的安全性十分重要。为研究钢筋混凝土柱抗水平冲击工作机理,运用有限元软件LS-DYNA建立精细化的数值模型对钢筋混凝土柱在水平冲击荷载作用下的动力响应进行模拟。通过与水平冲击试验结果对比验证了数值模型的可靠性,在此基础上重点分析了水平冲击荷载作用下钢筋混凝土柱的破坏形态、受力状态和加速度响应。研究表明:在水平冲击荷载作用下,钢筋混凝土柱的动力响应具有局部性和滞后性,其在冲击力达到峰值时未发生明显形变且未开裂;钢筋混凝土柱在冲击荷载作用下发生剪切破坏,其残余刚度和残余强度基本由纵筋提供,柱底固支端会出现拉压双向受力状态。

Reinforced concrete ( RC) columns are the main vertical load-bearing member,and it is very important to keep them safe when suffering horizontal impact loading from vehicle and tsunami debris. To investigate resistant mechanism of RC columns under horizontal impact loading,a elaborate numerical model is built by LS-DYNA to simulate the dynamic response of RC columns under impact loading. Simulation is verified through the comparison of experimental data and numerical results,and failure modes,mechanical state and response of acceleration are carefully analyzed. The numerical simulation show that the response of RC columns under horizontal impact loading is partial and delayed, they don’t have apparent deformation and cracks under the peak impact force. Impact loading will lead to shear failure,and it is the longitudinal bar of RC column that offers the residual stiffness and strength. The fixed bottom of RC column under impact will appear both tension and compression.