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数值模拟是研究混凝土动态力学性能主要手段之一。编写二维混凝土多边形粗骨料随机分布程序,利用大型有限元软件ANSYS/LS-DYNA对直径74mm、高70mm混凝土在不同冲击速度下的动态响应进行模拟,分析冲击速度、粗骨料最大粒径、最小粒径和体积含量对多边形粗骨料混凝土动态特性影响,考察多边形粗骨料混凝土动态破坏模式。数值模拟表明:混凝土表现出明显的率敏感性;随着粗骨料颗粒最小粒径增大,多边形粗骨料混凝土峰值应力逐渐减小;随着粗骨料颗粒最大粒径增大,多边形粗骨料混凝土峰值应力呈现先增大后减小趋势;当粗骨料体积含量小于40%时,随着粗骨料体积含量增加,多边形粗骨料混凝土峰值应力逐渐增大,当粗骨料体积含量大于40%时,随着粗骨料体积含量增加,多边形粗骨料混凝土峰值应力逐渐减小。
Numerical simulation is one of the main methods to study the dynamic mechanical properties of concrete. The program of random distribution of coarse aggregate with two-dimensional concrete polygons was prepared. The dynamic response of concrete with diameter of 74mm and height of 70mm at different impact velocities was simulated by ANSYS / LS-DYNA software. The effects of impact velocity, , The influence of the minimum particle size and volume content on the dynamic behavior of polygonal coarse aggregate concrete were investigated, and the dynamic failure mode of polygonal coarse aggregate concrete was investigated. Numerical simulations show that the concrete exhibits obvious rate sensitivity. With the increase of the minimum particle size of coarse aggregate, the peak stress of polygonal coarse aggregate concrete decreases gradually. With the increase of the maximum particle size of coarse aggregate, The peak stress of aggregate concrete firstly increases and then decreases. When the volume fraction of coarse aggregate is less than 40%, the peak stress of polygonal coarse aggregate concrete increases with the volume content of coarse aggregate. When the coarse aggregate volume When the content is more than 40%, the peak stress of polygonal coarse aggregate concrete decreases with the increase of coarse aggregate volume fraction.