Small specimens are increasingly being used in getting mechanical properties directly when there are limited materials to facilitate standard specimens,which play a great role in the rapid measurement of mechanical pr...Small specimens are increasingly being used in getting mechanical properties directly when there are limited materials to facilitate standard specimens,which play a great role in the rapid measurement of mechanical properties and residual life assessment of in-service reactor components.Although tensile and fatigue properties of the small specimens are investigated extensively,theoretical models for describing the mechanical properties of small specimens need to be established.Here,we conduct a systematic investigation of tensile and fatigue properties of pure Cu specimens with thicknesses ranging from 3 to 0.2 mm.The results show that the decrease in uniform elongation of the 0.2 mm-thick specimens is mainly due to the efects of grain boundary and free surface on the strain hardening rate.A modifed theoretical model correlated with the ratio of the surface grain layer thickness to the grain size is proposed to predict variation in yield strength of the small specimens more accurately.Furthermore,the mechanism for the diference in fatigue life between the 0.2 mm-thick specimen and other thicker specimens is elucidated.The Basquin equation-based model is presented as a potential way to evaluate the fatigue life of metals using small specimens.展开更多
采用T-F(Tests and finite element analysis)方法,通过小尺寸圆环试样单轴压缩试验,引入单轴本构关系模型进行有限元迭代计算使得模拟计算的试样变形与圆环试样压缩实验结果满足一致性,进而得到材料单轴弹塑性本构关系参数。研究表明,...采用T-F(Tests and finite element analysis)方法,通过小尺寸圆环试样单轴压缩试验,引入单轴本构关系模型进行有限元迭代计算使得模拟计算的试样变形与圆环试样压缩实验结果满足一致性,进而得到材料单轴弹塑性本构关系参数。研究表明,对不同厚度的304不锈钢圆环,应用T-F方法获得的材料本构关系与单轴拉伸试验结果吻合较好。基于小尺寸材料的T-F方法在获取小尺寸构件的力学性能方面有良好的工程应用前景。展开更多
基金supported by the National Natural Science Foundation of China(NSFC,No.52171128)the Fundamental Research Project of Shenyang National Laboratory for Materials Science(No.L2019R18).
文摘Small specimens are increasingly being used in getting mechanical properties directly when there are limited materials to facilitate standard specimens,which play a great role in the rapid measurement of mechanical properties and residual life assessment of in-service reactor components.Although tensile and fatigue properties of the small specimens are investigated extensively,theoretical models for describing the mechanical properties of small specimens need to be established.Here,we conduct a systematic investigation of tensile and fatigue properties of pure Cu specimens with thicknesses ranging from 3 to 0.2 mm.The results show that the decrease in uniform elongation of the 0.2 mm-thick specimens is mainly due to the efects of grain boundary and free surface on the strain hardening rate.A modifed theoretical model correlated with the ratio of the surface grain layer thickness to the grain size is proposed to predict variation in yield strength of the small specimens more accurately.Furthermore,the mechanism for the diference in fatigue life between the 0.2 mm-thick specimen and other thicker specimens is elucidated.The Basquin equation-based model is presented as a potential way to evaluate the fatigue life of metals using small specimens.
文摘采用T-F(Tests and finite element analysis)方法,通过小尺寸圆环试样单轴压缩试验,引入单轴本构关系模型进行有限元迭代计算使得模拟计算的试样变形与圆环试样压缩实验结果满足一致性,进而得到材料单轴弹塑性本构关系参数。研究表明,对不同厚度的304不锈钢圆环,应用T-F方法获得的材料本构关系与单轴拉伸试验结果吻合较好。基于小尺寸材料的T-F方法在获取小尺寸构件的力学性能方面有良好的工程应用前景。
