滚石冲击下孔隙率和孔隙分布对空心砖缓冲性能的影响

Effect of porosity and pore distributions on the cushioning mechanism of hollow brick subjected to boulder impact

采用大型摆锤冲击试验和LS-DYNA数值模型,研究了空心砖不同孔隙率(28%、42%、54%)和孔隙分布(2孔、8孔、18孔、32孔、50孔)对空心砖缓冲性能的影响。结果表明:滚石冲击力随着空心砖孔隙率的增大而减小,54%孔隙率空心砖比28%孔隙率空心砖减小了23%滚石冲击力峰值和46%空心砖缓冲层传递力峰值;滚石冲击力和空心砖缓冲层传递力随着孔隙分布均匀化而减小,相比于2孔空心砖,50孔空心砖最大可减小46%滚石冲击力,传递力可减小31%;均匀的孔隙结构分布可以有效增大传递力扩散角,50孔空心砖比2孔空心砖传递力扩散角增大46%。

The large scale pendulum impact test and LS-DYNA numerical model were used to study the effects of different porosity(28%,42%and 54%)and pore distribution(2 holes,8 holes,18 holes,32 holes and 50 holes)on the cushioning performance of hollow bricks.The results show that the impact force of rolling rock decreases with the increase of the porosity of hollow brick,and the peak value of impact force of rolling rock and the peak value of transfer force of hollow brick buffer layer of 54%porosity hollow brick are reduced by 23%and 46%,respectively,compared to those of 28%porosity hollow brick.The impact force of rolling rock and the transmission force of hollow brick buffer layer decrease with the homogenization of pore distribution.Compared with 2 hole hollow brick,the maximum impact force of 50 hole hollow brick can be reduced by 46%and the transmission force can be reduced by 31%.In addition,the uniform pore structure distribution can effectively increase the transfer force diffusion angle.The transfer force diffusion angle of 50 hole hollow brick is 46%larger than that of 2 hole hollow brick.