基于超材料的动态压剪复合加载实验新技术  

A new experimental technique of dynamic compression-shear combined loading based on metamaterials

作　　者：任清非 张泳柔 胡玲玲 尹梓霁 REN Qingfei;ZHANG Yongrou;HU Lingling;YIN Ziji(School of Aeronautics and Astronautics,Sun Yat-sen University,Shenzhen 518107,Guangdong,China)

机构地区：[1]中山大学航空航天学院,广东深圳518107

出　　处：《爆炸与冲击》2024年第10期1-18,共18页Explosion and Shock Waves

基　　金：国家自然科学基金(12172388)。

摘　　要：材料或结构在动态压剪复合加载条件下的力学性能对于其工程应用具有重要影响。然而,现有的动态复合加载实验技术存在压缩波和剪切波难以同步施加到试件、实验设备昂贵等问题。本文中利用压扭超材料进行应力波转化,在一维分离式霍普金森压杆(split Hopkinson pressure bar,SHPB)上实现动态压剪同步复合加载。该实验技术具有荷载精准同步、剪压比可控、简单便捷、低成本等优点。针对当压扭超材料转化出来的扭转波幅值较大,透射杆惯性约束不足情况下出现的扭转信号三角波的问题进行详细讨论,并提出相应的解决方案。选用屈服应力各不相同的金属钛、304不锈钢和316L不锈钢等3种材料进行了实验测试,证实了动态压剪同步复合加载技术的有效性。借助有限元模型,深入分析压扭超材料的几何参数对其压扭系数及承载能力的影响,并结合实验结果讨论了该实验技术的适用范围,预测动态压剪同步复合加载技术能测试的材料强度可达约1 GPa,施加给试件的剪压比可达1.18。The mechanical properties of materials or structures under dynamic compression-shear combined loading conditions significantly influence their engineering applications.However,existing experimental methodologies for dynamic combined loading confront challenges,such as the difficulty in synchronously applying compression and shear waves to test specimens,in addition to the high cost of experimental equipment.This study introduces a novel experimental technique that utilizes compression-torsion coupling metamaterials for the conversion of stress waves,enabling synchronous dynamic compression-shear combined loading on a one-dimensional Hopkinson pressure bar.This technique offers several advantages,including precise load synchronization,a controllable shear-compression ratio,simplicity,convenience,and low cost.A detailed discussion is presented on the issue of triangular torsion signals that arise when the amplitude of torsional waves converted from compression-torsion metamaterials reaches considerable levels,coupled with insufficient inertial confinement in the transmission bar of the split Hopkinson pressure bar system.Additionally,corresponding solutions to this issue are proposed.Experimental tests were conducted on three materials with distinct yield stresses:titanium,304 stainless steel,and 316L stainless steel,validating the effectiveness of this experimental technique.Furthermore,leveraging finite element models,an in-depth analysis was conducted on the influence of the geometric parameters of the compression-torsion coupling metamaterials on their compression-torsion coefficients and load-bearing capacities.By integrating these findings with experimental results,the applicability of this experimental technique was discussed,predicting its capability to test materials with strengths up to approximately 1 GPa and to apply shear-compression ratios up to 1.18 to specimens,providing a reference for its application in a broader range of fields.This innovative integration of metamaterials with traditional experim

关 键 词：动态压剪复合加载 压扭超材料 分离式霍普金森压杆 应力波转化 

分 类 号：O347.1[理学—固体力学]