Determination of dynamic elastic modulus of polymeric materials using vertical split Hopkinson pressure bar
| Autor: | Long Zhao, Yong-Jian Mao, Hong-Yuan Liu, Yiu-Wing Mai, Yazhou Guo, Wei Qi, Qiong Deng, Yulong Li, Tao Suo, Luming Shen, Yinggang Miao, Fa-Qin Xie, Haitao Hu |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
Bar (music) Mechanical Engineering Young's modulus 02 engineering and technology Split-Hopkinson pressure bar Epoxy 021001 nanoscience & nanotechnology Condensed Matter Physics Stress (mechanics) symbols.namesake 020303 mechanical engineering & transports Tilt (optics) 0203 mechanical engineering Mechanics of Materials Indentation visual_art symbols visual_art.visual_art_medium General Materials Science Composite material 0210 nano-technology Elastic modulus Civil and Structural Engineering |
| Zdroj: | International Journal of Mechanical Sciences. :188-196 |
| ISSN: | 0020-7403 |
| DOI: | 10.1016/j.ijmecsci.2016.02.005 |
| Popis: | This paper is focused on the determination of dynamic elastic modulus of polymer materials under high strain rate loading using the split Hopkinson pressure bar (SHPB) technique. Experiments conducted on the epoxy specimen by the traditional SHPB and the proposed vertical SHPB equipment demonstrates that the vertical SHPB can give more accurate measurements. The related factors, namely, the effect of stress inequilibrium in specimen, indentation in bars due to specimen and the tilt between specimen and bars, are extensively studied. It is concluded through theoretical analysis and numerical calculations that the influence of stress inequilibrium becomes negligible after two characteristic times. The numerical study on the indentation effect shows that the bar to specimen specific elastic modulus ratio and specific diameter ratio are critical to the level of influence on indentation. However, polymers with low elastic modulus values can still be accurately measured regardless of the indentation displayed. The numerical investigation on tilt effect indicates that the imperfect contact condition severely affects the accuracy of measured elastic modulus. This issue can be rectified by the newly proposed vertical SHPB. It can improve the contact conditions between bars and specimen significantly and offer acceptable accurate measurements for the dynamic elastic modulus of polymeric materials. |
| Databáze: | OpenAIRE |
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