Measurement of Stress-strain Relation by Means of Instrumented Charpy Impact Bending

通过仪器化夏比冲击弯曲测量应力-应变关系

• 批准号: 06650097
• 负责人: CHATANI Akiyoshi
• 金额: $ 1.02万
• 依托单位: Kanazawa University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06650097/
• 关键词: Dynamic stress-strain relation; Instrumented Charpy impact test; Impact load; Simple plastic bending theory; 計装化シャルピー衝撃試験法; 衝撃荷重推定

Some experimental studies on the measurement of stress-strain relations by means of Charpy impact bending were carried out and the practical application of them were discussed. Stress-strain relations obtained are based on the simple plastic bending theory of a beam specimen under instrumented Charpy impact bending, where the statics is supposed in determining the impact bending moment from the impact load estimated by impact response function of convolutional integral and the bending strain is measured by a strain gage cemented to the back side of impact point. The present results using various specimens were compared with those by impact compression of Hopkinson bar type. As a result, it was found that the present method was available except for the case of small strain or low strength materials, though more or less fluctuations were seen in stress-strain relation obtained. Furthermore dynamic stress-strain relations of heat treated steel alloys with high hardness were obtained by the present method. So the strain rate and the hardness dependency of yield or fracture strengths of them was studied. According to the result the strength becomes maximum at Vickers hardness HV600-700 and it is not so affected by strain rate.

本文对夏比冲击弯曲法测定应力-应变关系进行了实验研究，并讨论了其实际应用。应力-应变关系是基于简支梁简支梁冲击弯曲的简单塑性弯曲理论得到的，其中冲击弯矩由卷积积分的冲击响应函数估算，而弯曲应变由粘贴在冲击点背面的应变片测量。并与Hopkinson杆式冲击压缩试验结果进行了比较。结果表明，虽然应力-应变关系存在或多或少的波动，但本方法对小应变或低强度材料是有效的。此外，还得到了高硬度钢合金热处理后的动态应力-应变关系。因此，应变速率和硬度的屈服或断裂强度的依赖关系进行了研究。结果表明，在维氏硬度HV 600 -700范围内，强度达到最大值，应变速率对强度影响不大。