作者：曲嘉¹, 李东昌¹, 黄超²

作者单位：1. 哈尔滨工程大学, 黑龙江 哈尔滨 150001;
2. 哈尔滨理工大学, 黑龙江 哈尔滨 150080

关键词：数字图像相关;动态断裂韧性;分离式霍普金森压杆;不锈钢

摘要：

高速冲击动态断裂韧性的加载和测试技术一直是近年关注的热点，随着计算机和光学传感器的发展，采用数字图像相关方法测量材料的动态断裂韧性已成为重要选择。该文基于分离式Hopkinson压杆原理的加载技术，通过高速摄影机拍摄高速冲击下三点弯曲试样裂纹的起裂和扩展，运用数字图像相关技术分析裂尖场的散斑图像，计算得到相应的应变场变化，试样外表面处于平面应力状态，其裂尖应变场呈现0型，而非试样对称面所处于的平面应力状态下呈8型。结果表明，DIC技术可以应用于动态断裂韧性实验，也证明裂尖场粘贴的应变片测量试样起裂的有效性。

Application of digital image correlation method in dynamic fracture toughness testing

QU Jia¹, LI Dongchang¹, HUANG Chao²

1. Harbin Engineering University, Harbin 150001, China;
2. Harbin University of Science and Technology, Harbin 150080, China

Abstract: The high speed dynamic fracture toughness loading and testing technology has become the focus of the public.With the development of computer and optical sensors,measuring the dynamic fracture toughness of materials with digital image correlation method has become an important choice.Based on the principle of split Hopkinson pressure bar (SHPB) loading technique,a high-speed camera was used to photograph crack initiation and propagation process of three-point bending specimen under high-speed shocking,and analyze the speckle image of crack tip by digital image correlation method.The developing processing of strain field was obtained.In conclusion,the outside surface of the specimen is in plane stress state and the strain field of the crack tip is in "0" shape instead of the "8" shape.The results showed that the DIC technique could be applied to the dynamic fracture toughness test,and it also proves the effectiveness of the strain gage measuring the crack initiation.

Keywords: digital image correlation;dynamic fracture toughness;SHPB;stainless steel

2016, 42(10): 45-48  收稿日期: 2016-5-3;收到修改稿日期: 2016-6-19

基金项目: 国家自然科学基金（11302055）哈尔滨市科技创新人才专项基金（2013RFQXJ009）

作者简介: 曲 嘉(1979-),男,黑龙江哈尔滨市人,副教授,博士,研究方向为冲击动力学及强度理论。

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