Evaluation of high-temperature tensile behavior for metal foils by a novel resistance heating assisted tensile testing system using samples with optimized structures
Evaluation of high-temperature tensile behavior for metal foils by a novel resistance heating assisted tensile testing system using samples with optimized structures
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DOI：
10.1016/j.jmst.2021.03.061
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发表时间：
2021
影响因子：
10.9
通讯作者：
Q. Zheng;T. Furushima
中科院分区：
文献类型：
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作者：
Q. Zheng;T. Furushima
为了准确评价电阻加热（RH）辅助拉伸试验系统对金属箔拉伸性能的影响，提出了一种嵌入激光散斑数字图像相关（DIC）系统的应变全场测量方法。此外，样品结构进行了优化，以实现均匀的温度和应变分布。采用红外摄像机监测温度分布。提出用矩形试样代替狗骨形试样。建立了温度分布计算模型，优化了样品结构。研究了影响温度分布和拉伸行为的参数。结果，与非接触式引伸计测量的应变相比，当标称应变大于0.013时，DIC测量的应变的最大偏差小于6%。实验结果表明，所设计的拉伸试验系统能够可靠地测量温度和全场应变分布。试样形状对小尺寸试样的温度分布有影响，而对大尺寸试样的温度分布几乎没有影响。温差不受材料类型的影响，但受样本量的影响。所提出的矩形形状经验证对于RH辅助拉伸试验是可行的。利用所建立的模型对试样长度进行了优化，使试样的温度分布更加均匀.虽然拉伸变形不受样品形状的影响，但温度分布导致在达到极限拉伸强度之前应变分布不均匀。夹具间有效长度越长，温度分布越均匀，材料变形越大。采用优化结构的矩形试样，建立了RH辅助拉伸试验系统，可以更准确地评价金属箔的高温拉伸性能。
To evaluate the tensile behavior of metal foils by resistance heating (RH) assisted tensile testing system accurately, this study proposed to embed a digital image correlation (DIC) system with laser speckles for the measurement of full-field strain distribution. Furthermore, the sample structures were optimized to achieve uniform temperature and strain distribution. An infrared camera was used to monitor the temperature distribution. Rectangular samples instead of dog-bone shaped samples were proposed. A model for calculating the temperature distribution was established to optimize the sample structure. The parameters that influence the temperature distribution and tensile behavior were studied. As results, compared to the strain measured by a non-contact extensometer, the maximum deviation of the strain measured by DIC was less than 6% when the nominal strain was larger than 0.013. It is confirmed that the proposed tensile testing system is reliable for measuring the temperature and full-field strain distributions. Sample shape influenced temperature distributions of smaller samples while it almost had no influence on the temperature distributions of larger samples. The temperature difference was not affected by the material type but by the sample size. The proposed rectangular shape was validated to be feasible for RH assisted tensile testing. The sample length was successfully optimized for a more uniform temperature distribution by the established model. Although the tensile deformation was not influenced by the sample shape, the temperature distribution resulted in a non-uniform strain distribution before achieving ultimate tensile strength. Longer effective sample length between two clamping jigs contributed to a more uniform temperature distribution and material deformation. A more accurate evaluation of high-temperature tensile behavior for metal foils can be achieved by the proposed RH assisted tensile testing system using rectangular samples with an optimized structure.