颗粒混凝土材料在建筑结构中应用比较常见，但其冲击下的动力学性能研究欠缺。为得到颗粒混凝土的动力学特性，借助MTS实验机得出其静力学强度，其后使用直径为75 mm SHPB系统对颗粒混凝土试样做了多种加载速度下的冲击试验。结果表明，颗粒混凝土试样的毁坏模式是非脆性碎裂，呈现出延性特点;随着冲击速度的增大，破坏后的形状由试样被压扁(形态基本完整，表现出明显的可压缩性)过渡到絮状。应变率在103。88～464。71 s-1时，试样的峰值应力随着应变率的变大而增大，表现出明显的应变率效应。根据实验现象和实验数据进行分析，推导建立了颗粒混凝土峰值应力前和峰值应力后应力-应变的等效本构方程，将实验数据与拟合数据进行对比，具有较为明显的一致性，验证了本构方程的准确性。
Experimental study on dynamic mechanical properties of granular concrete under impact compression
In the past,the use of granular concrete materials in building structures was common,but research on the dynamic performance under impact was lacking.To obtain the dynamic characteristics of granular concrete,the static strength was first obtained using an MTS testing machine.Subsequently,various impact tests were conducted on granular concrete specimens using an SHPB system with a diameter of 75 mm and different loading rates.The results showed that the failure mode of the granular concrete specimens was non-brittle fragmentation,exhibiting ductile characteristics.As the impact velocity increased,the post-failure shape transitioned from a flattened sample(with relatively intact form,showing obvious compressibility)to a fluffy state.At strain rates between 103.88 s-1 and 464.71 s-1,the peak stress of the specimens increased with the increasing strain rate,displaying a significant strain rate effect.Based on the analysis of experimental phenomena and data,an equivalent constitutive equation for stress-strain before and after peak stress of granular concrete was derived and established.A comparison between experimental and fitted data showed significant consistency,confirming the accuracy of the constitutive equation.
万方数据
维普
