冲击荷载作用下混凝土动态力学性能数值模拟研究

利用直锥变截面式Φ74 mm SHPB对混凝土和水泥砂浆材料进行了三种不同冲击速度下的动态力学性能实验，分析了其冲击速度对混凝土力学性能的影响规律。应用刚性板冲击加载的方式进行了混凝土动力响应的数值模拟研究，数值模拟结果与实验结果吻合较好。数值模拟表明：混凝土的峰值应力随着冲击速度的增大而增大，混凝土是一种率敏感材料；随着粗骨料体积含量增大，冲击荷载作用下混凝土的峰值应力呈现先增大后减小的趋势，粗骨料体积含量为40%时混凝土峰值应力最大；保持粗骨料最大粒径不变，随着粗骨料最小粒径的增大，混凝土的峰值应力逐渐减小；保持粗骨料最小粒径不变，随着粗骨料最大粒径的增大，混凝土的峰值应力呈现先增大后减小的趋势，数值模拟结果为混凝土的工程应用提供了理论依据和技术支撑

Research on the Numerical Simulation of Dynamic Mechanical Behaviors of Concrete Subjected to Impact Loading

SHPB with the diameter of 74mm was used to study the dynamic mechanical properties of cement mortar and concrete under different impact velocities. The influence of impact velocity on the mechanical properties of concrete was analyzed. The dynamic response of concrete was simulated, which was loaded by rigid slab. The simulation results agreed well with experimental results. Numerical simulation shows that the peak stress of concrete increases with impact velocity, so concrete is rate-dependent. With the increase of the volume fraction of coarse aggregate, the peak stress of concrete increases firstly, then declines. When the volume fraction of coarse aggregate is equal to 40%, the peak stress of concrete is maximum value. Under the condition that the maximum diameter of coarse aggregate is kept unchanged, the peak stress of concrete declines with the minimum diameter of coarse aggregate. However, under the condition that the minimum diameter of coarse aggregate is kept unchanged, with the increase of the maximum diameter of coarse aggregate, the peak stress of concrete increases firstly, then declines, which provides theoretical guidance for the engineering application of concrete