基于SHPB试验的多尺寸大理岩动态力学性能研究

为研究多尺寸大理岩的动态力学性能，基于SHPB试验采用理论分析、数值模拟、室内试验等方法深入分析了尺寸对大理岩动态力学性能的影响。通过室内试验和数值模拟，验证了LS DYNA中使用HJC本构模型研究大理岩冲击荷载作用下破坏过程、应力波形特征等的合理性；利用LS DYNA软件对同一长径比、3种不同直径的大理岩在4种不同冲击速度下展开研究。结果表明：大理岩动态强度随其直径的增加而减小，随冲击速度的增加而增大；在冲击压缩试验中，大理岩以沿轴向劈裂拉伸破坏为主，其破坏滞后于应力峰值，滞后于应力峰值的时间会随冲击速度的增加而减小；室内试验和数值模拟结果均表明，当压杆直径不变时，大理岩的尺寸对SHPB试验结果中大理岩动态强度具有重要影响，其动态强度随其长径比的增大先增加后减小。

Study on Dynamic Mechanical Properties of Multi-size Marble Based on SHPB Test

In order to study the dynamic mechanical properties of multi dimensional marble,theoretical analysis,numerical simulation and laboratory experiments were used to analyze the influence of size on the dynamic mechanical properties of marble based on SHPB test.Through laboratory tests and numerical simulation,the rationality of using HJC constitutive model in LS DYNA to study the failure process and stress waveform characteristics of marble under impact load is verified.The lS DYNA software is used to study marble with three different diameers of the same aspect ratio under four different impact velocities.The results show that the dynamic strength of marble decreases with the increase of its diameter and increases with the increase of impact velocity.In the impact compression test,the main failure of marble is axial split tensile failure,and the failure time lags behind the stress peak,which decreases with the increase of impact velocity.The results of laboratory tests and numerical simulation show that the size of marble has an important effect on the dynamic strength of marble in SHPB test when the diameter of pressure bar is constant,and the dynamic strength of marble increases first and then decreases with the increase of its aspect ratio.