Strain measuring accuracy with splitting-beam laser extensometer technique at split Hopkinson compression bar experiment

Bulletin of the Polish Academy of Sciences. Technical Sciences

J. JaniszewskiMilitary University of Technology, 2 Gen. Kaliskiego Str., 00-908 Warsaw, PolandOther articles by this author:De Gruyter OnlineGoogle Scholar¹  R. PanowiczCorresponding authorMilitary University of Technology, 2 Gen. Kaliskiego Str., 00-908 Warsaw, PolandEmailOther articles by this author:De Gruyter OnlineGoogle Scholar¹  M. TraczykMilitary University of Technology, 2 Gen. Kaliskiego Str., 00-908 Warsaw, PolandOther articles by this author:De Gruyter OnlineGoogle Scholar¹ 

[1] Military University of Technology, 2 Gen. Kaliskiego Str., 00-908 Warsaw, Poland

关键词: Keywords: SHPB test;    strain rates;    non-contact strain measurement;    laser extensometer;   

DOI  :  10.1515/bpasts-2017-0020

学科分类：工程和技术（综合）

来源: Polska Akademia Nauk * Centrum Upowszechniania Nauki / Polish Academy of Sciences, Center for the Advancement of Science

【 摘 要 】

An accuracy problem of strain measurement at compression split Hopkinson compression bar experiments with a splitting-beam laser extensometer was considered. The splitting-beam laser extensometer technique was developed by Nie et al. to measure strain of a specimen during its tension under a high strain rate loading condition. This novel concept was an inspiration for the authors to develop own laser extensometer system, which allows for simultaneous and independent measurement of displacement of bar ends between which a compressed material specimen is placed. In order to assess a metrological property of this measuring system, a wide range of high strain rate experiments were performed, including tests with various sample materials (Al 5251, Cu OFE) with different rate of strain, and with the use of two bars material. A high accuracy of the developed laser extensometer was found in measurement of specimen strain, for which uncertainty is not greater than 0.1% and, for a typical specimen dimension, the maximum permissible error is 4.5 μm.

【 授权许可】

Unknown