Two types of coal samples' dynamic mechanical properties under impact loading

2nd International Conference on Materials Science, Energy Technology and Environmental Engineering

材料科学;能源学;生态环境科学

Li, Zhongqing^1 ; Liu, Zegong^1 ; Mu, Chaomin^1 ; Zhang, Wenqing^1

School of Energy Resources and Safety, Anhui University of Science and Technology, Huainan, Anhui

232001, China^1

关键词: Dynamic mechanical property;    Dynamic stress-strain relation;    Impact loadings;    Kinetic experiment;    Split Hopkinson pressure bar test systems;    Strain rate effect;    Strain-rate hardening;    Toughening effects;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/81/1/012078/pdf
DOI  :  10.1088/1755-1315/81/1/012078

来源: IOP

【 摘 要 】

This study presents a kinetic experiment process of briquette and raw coal samples in detail by means of Φ 75mm split Hopkinson pressure bar test system and dynamic stress-strain relations and mechanical properties of this two different coal samples. According to the experimental results, this two coal samples both have strain rate effect. The DIF (dynamic stress increasing factor) and DEIF (dynamic strain increasing factor) of the two coal samples have different trends. There is a turning phenomenon of DIF as the strain rate is around 100s-1, and the DIF of the hard coal increases rapidly over 100s-1, but the DIF increasing rate of soft coal has little change before or after the turning point. The DEIF of the two types of coal all increases with the increase of strain rate, but the turning strain rate of ordinary coal is 120s-1, while a platform of turning strain rate exists for outburst coal with strain rate ranging from 100s-1to 210s-1. It represents the discrepancy in their strain rate hardening effect and dynamic toughening effect.