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。
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.
作者
曲嘉
李东昌
黄超
QU Jia LI Dongchang HUANG Chao(Harbin Engineering University,Harbin 150001, China Harbin University of Science and Technology, Harbin 150080, China)
出处
《中国测试》
CAS
北大核心
2016年第10期45-48,共4页
China Measurement & Test
基金
国家自然科学基金(11302055)
哈尔滨市科技创新人才专项基金(2013RFQXJ009)
