Dynamic characterization of micro scale samples using the Hopkinson tensile technique
When the conventional split Hopkinson bar technique is applied to obtain the dynamic tensile property of small and soft materials, such as foils, fibers and yarns, the mechanical impedance mismatch between the bars and the tested materials restricts the maximum achievable strain and the high noise-to-signal ratio prevents correct registration of the transmitted pulse. To overcome these difficulties, a mini-split Hopkinson tensile bar (mSHTB) system is developed. The system employs polymeric bars with small diameter, which can achieve a closer impedance match with the specimens, thus it provides a lower noise-to-signal ratio and a longer duration of tensile pulse, which results in a higher maximum strain. Linear visco-elastic equations are established to correct the dispersion and attenuation of waves propagating in a visco-elastic bar. As examples of the testing results, dynamic stress-strain curves at strain rates in the range of 102～103 s-1 for polycarbonate foils, cellulose nitrate foils and multi-walled carbon nanotube reinforced ultra-high molecular weight polyethylene (MWCNT/UHMWPE) composite fibers are presented.
Ming Yan Leung Xin-long Dong T. X. Yu
Department of Mechanical Engineering, Hong Kong University of Science And Technology,Clear Water Bay Department of Mechanical Engineering, Hong Kong University of Science And Technology,Clear Water Bay
国际会议
The 5th International Conference on Nonlinear Mechanics(第五届国际非线性力学会议)
上海
英文
1292-1298
2007-06-11（万方平台首次上网日期，不代表论文的发表时间）