沙漠砂混凝土动态力学性能数值模拟

沙漠砂混凝土动态力学性能非常复杂,利用SHPB进行沙漠砂混凝土动态冲击压缩试验,分析冲击速度对沙漠砂混凝土动态性能影响规律。编写沙漠砂混凝土圆形骨料随机分布程序,运用ANSYS/LS-DYNA软件对试件尺寸、冲击速度、粗骨料体积含量和粗骨料颗粒大小不同沙漠砂混凝土动态破坏过程进行模拟,分析试件尺寸、冲击速度、粗骨料体积含量和粗骨料颗粒大小对沙漠砂混凝土动态力学性能的影响规律。数值模拟表明:沙漠砂混凝土具有明显尺寸效应;随着粗骨料颗粒最小粒径增大,沙漠砂混凝土峰值应力逐渐减小;随着粗骨料颗粒最大粒径增大,沙漠砂混凝土峰值应力呈先增大后减小趋势;随着粗骨料体积含量增大,沙漠砂混凝土峰值应力呈先增大后减小趋势,数值模拟结果为沙漠砂混凝土优化设计提供依据。

Numerical simulation of dynamic mechanical behaviors of desert sand concrete

The dynamic mechanical behaviors of desert sand concrete are very complicated. 74mm-diameter Split Hopkinson pressure bar (SHPB) was used to study the mechanical behaviors of desert sand concrete under various impact speeds in this paper. The influence of impact speed on the dynamic mechanical behav-iors of desert sand concrete was analyzed. A circular aggregate random distribution program was designed to simulate the dynamic failure process of desert sand concrete with different specimen dimension, impact speed,particle size of coarse aggregate and volume fraction of coarse aggregate by means of ANSYS/LS-DY-NA software. The influences of specimen dimension,impact speed,particle size of coarse aggregate and vol-ume fraction of coarse aggregate on the dynamic mechanical behaviors of desert sand concrete were ana-lyzed. Numerical simulation shows that desert sand concrete has obvious size effect. With the increase of the minimum value of particle size of coarse aggregate, the peak stress of desert sand concrete declines. Whereas, with the increase of the maximum value of particle size of coarse aggregate, the peak stress of desert sand concrete increases firstly,then declines. The peak stress of desert sand concrete increases first-ly, and then declines with the volume fraction of coarse aggregate, which provides basis for optimization and design of desert sand concrete.