Wave dispersion analysis and simulation method for concrete SHPB test in peridynamics
Wave dispersion analysis and simulation method for concrete SHPB test in peridynamics
复制标题
混凝土SHPB近场动力学试验波频散分析与模拟方法
DOI：
10.1016/j.engfracmech.2016.04.005
复制
发表时间：
2016-07-01
影响因子：
5.4
通讯作者：
Yv, Yangtian
中科院分区：
文献类型：
--
作者：
Gu, Xin;Zhang, Qing;Yv, Yangtian
劈裂霍普金森压杆（Split Hopkinson Pressure Bar， SHPB）技术是一种广泛应用于材料在高应变率载荷作用下力学性能测试的方法，但常规数值方法难以模拟材料的高应变率变形、局部损伤和破坏等整个测试过程。本文采用基于非局部周动力理论的改进数值方法，研究了混凝土巴西盘在SHPB试验中弹性波的频散、传播和冲击破坏。同时，介绍了一种改进的PMB模型及其接触-冲击过程的实现方法。在PD中，非局域长程力控制着波在不同质点尺寸和水平尺寸下的数值色散。数值色散会导致波速和裂纹扩展速度的轻微畸变，这不利于固体的破坏分析。与原PMB模型相比，改进的PMB模型能有效地减小数值色散。此外，混凝土巴西盘SHPB试验的PD模拟可以再现试件的损伤累积和渐进破坏，并产生典型的最终破坏模式。SHPB试验的PD模拟方法可用于分析固体在冲击载荷作用下的动态响应。(C) 2016 Elsevier Ltd.版权所有。
The Split Hopkinson Pressure Bar (SHPB) technique is a widely used method for measuring mechanical properties of materials subjected to high-strain-rate loads, while it is difficult to simulate the whole testing process including high-rate deformation, local damage and failure of materials by the common numerical methods. In this paper, an improved numerical approach based on the non-local peridynamic (PD) theory is employed to study the elastic wave dispersion and propagation and the impact failure of concrete Brazilian discs in SHPB test. Meanwhile, an improved PMB (Prototype Microelastic Brittle) model and an implementation method of the contact-impact process are introduced. In PD, the nonlocal long-range force controls the numerical dispersion of wave through different material point sizes and horizon sizes. The numerical dispersion can result in a slight distortion of the wave speed and crack propagation speed, which is not conductive to failure analysis of solids. The improved PMB model can effectively lessen the numerical dispersion compared with the original PMB model. Furthermore, the PD simulation of concrete Brazilian disc SHPB test can reproduce damage accumulation and progressive failure of a specimen, and produce typical final failure pattern. The PD simulation method for SHPB test can be used to analyze the dynamic response of solids suffering impact load. (C) 2016 Elsevier Ltd. All rights reserved.