文献类型：期刊文献

英文题名：Effect of stress regime-dependent creep behaviour on measurement of creep strain rate based on small specimen techniques

作者：Tu, Shan-Tung[1];Zhang, Kun[1];Bai, Yu[1];Tan, Jian-Ping[1];Deng, Guo-Jian[2]

机构：[1]East China Univ Sci & Technol, Sch Mech & Power Engn, MOE Key Lab Pressure Syst & Safety, Shanghai 200237, Peoples R China;[2]Aero Engine Grp Corp China, Commercial Aircraft Engine Co Ltd, Shanghai Engn Res Ctr Commercial Aircraft Engine, Shanghai 200241, Peoples R China

年份：2019

卷号：42

期号：1

起止页码：187

外文期刊名：FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES

收录：;EI(收录号：20183505758981);WOS:【SCI-EXPANDED(收录号:WOS:000452237300015)】；

基金：National Natural Science Foundation of China, Grant/Award Numbers: 51705492, 11502082 and 11472105; Shanghai Technology Innovation Program of SHEITC, Grant/Award Number: CXY-2015-001; Science and Technology Commission of Shanghai Municipality, Grant/Award Number: 16DZ2260600

语种：英文

外文关键词：creep mechanism; creep testing; finite element analysis; measurement error; small specimen technique

摘要：Small specimen creep testing technique has become a hot topic of research as bulk materials are not available in many occasions. The stress distributions in the small specimens such as small punch and 3-point bending specimens are essentially nonuniform. As it is known, the creep deformation/damage accumulation mechanisms exhibited at a high stress regime are not the same as the ones at a lower stress regime for many engineering alloys. The potential measurement errors because of stress regime-dependent creep behaviour, however, has not been considered in the determination of the creep parameters based on small specimen testing in the previous studies. In this paper, 2 kinds of materials that show different Norton's parameters at the corresponding stress regimes are examined. A simple case of 2-bar structure is firstly adopted to illustrate the measurement error of creep strain rate because of stress regime-dependent creep behaviour. Furthermore, clamped beam bending testing and small punch testing are investigated to demonstrate the significance of measurement error using the same materials. It is shown that an error of more than 8 times may occur near the transition point of creep deformation mechanism depending on specimen types and materials. Attention should thus be paid to the selection of stress level in the small specimen testing to avoid significant measurement errors.