A method of spherical indentation experiment based on the split Hopkinson pressure bar system
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摘要: 提出一种基于霍普金森压杆装置的动态球形压痕实验方法，通过将硬质合金小球置于2个试件中间，实现加载过程中2个试件的同时压入，以得到准确的压痕力与位移的关系。利用有限元软件ABAQUS/Explicit对该实验方法进行了数值模拟，从实验结果的可行性、准确性等方面，对新实验方法与传统的动态压痕实验方法进行了比较；采用新方法对铝合金材料进行了实验，并得到了压入力-位移曲线等关系。研究结果表明：采用新实验方法能得到较准确的结果，能较真实地描述压痕过程。Abstract: A new technique for testing dynamic spherical indentation of materials was proposed.It was implemented by putting a WC alloy ball between two specimens, one of which was bonded with the input bar and the other was bonded with the output bar.Then the two speciemens were pressed in the process of indentation.With this simple arrangement we can accomplish a very accurate measurment of force and displacement during the indentation.A finite element simulation was carried out by using the ABAQUS/Explicit software to evaluate this new experimental technique.The results show that the new method gives a more accurate result than other dynamic indent experimental methods.In addition, by testing the alumimum alloy materials, the curves of the indentation force and depth were gotten based on the new technique.The investigation diaplays that the technique proposed can porvide more accuate results and refect the indentation process more truely.
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Key words:
- solid mechanics /
- spherical indentation /
- SHPB /
- indentation experiment
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图 2 试件加载方式和位移测量基准点
Figure 2. Specimen loading patterns and reference points for displacement measurement
图 3 计算压痕深度与基准点测量压痕深度比较(Nilsson方法)
Figure 3. Calculated indentation depths compared with the ones measured from the refence points (in Nillson's method)
图 4 计算压痕深度与基准点测量压痕深度比较(本文方法)
Figure 4. Calculated indentation depths compared with the ones measured from the refence points (in this paper)
图 5 采用本文方法得到接触过程中的Misses应力云图
Figure 5. Misses stress contours in the contact process using the method in this paper
图 7 双试件新方法的波形处理结果
Figure 7. Waveforms aquired by using the new method with double specimens
表 1 杆件及试件的弹性参数
Table 1. Elastic constants of the bars and the specimens
材料 E/GPa μ ρ/(g·m-3) 60Si2Mn 206 0.29 7.80 45钢 210 0.29 7.80 铝合金 71 0.28 2.70 碳化钨 450 0.28 18.00 
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表 2 试件的J-C本构参数
Table 2. J-C constants of specimens
材料 A/MPa B/MPa C n m 45钢 1 150 739 0.014 0.26 1.03 铝合金 369 684 0.008 3 0.73 1.70
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