Measurement of transient temperature at super-high-speed deformation

• Published in: International journal of mechanical sciences 2021-09, Vol.206, p.106626, Article 106626
• Main Authors: Gao, Chong, Iwamoto, Takeshi
• Format: Article
• Language: English
• Subjects: Impact compression; Infrared detector; Miniature split Hopkinson pressure bar; Pure aluminium; Temperature change; Thermocouple
• ISSN: 0020-7403; 1879-2162
• DOI: 10.1016/j.ijmecsci.2021.106626

•The unknown temperature rise of aluminium at super high strain rate is measured.•The miniature SHPB technique is employed to achieve the super high strain rate.•The unclear applicability of the thermocouple and infrared detector are discussed.•Both the thermocouple and infrared detector have a high responsiveness. To evaluate the thermal behaviour of the materials at high strain rate, the thermocouple and infrared detector are widely employed for measuring the temperature rise in the strain rate range of 103 s−1. However, it is hard to find challenges on measuring the temperature rise over 104 s−1 of the strain rate. Here, both the type-T thermocouple with 80 μm in tip diameter and the infrared detector are introduced into a miniaturized testing apparatus based on the split Hopkinson pressure bar technique which is employed to achieve 104 s−1 of the strain rate for measuring the temperature rise of the materials. The responsiveness of thermocouple and infrared detector is discussed based on the stress waves propagating in Hopkinson pressure bars. Then, the applicability of the thermocouple and infrared detector is also discussed by comparing the results obtained by a finite element simulation using commercial software and theoretical calculations. As a result, both the techniques have a high responsiveness and can be applied to measure the temperature rise in the strain rate range of 104 s−1. [Display omitted]