数字图像相关测量钢绞线的弹性模量

Elastic Modulus Measurement of Strand Wire Using Digital Image Correlation

利用数字图像相关方法(Digital Image Correlation,DIC),测定了钢绞线的拉伸弹性模量.采用CCD及其计算机处理系统,采集不同载荷下钢绞线的数字图像.对所采集的系列数字图像进行相关运算获得位移,用线性平面拟合位移场获得平均应变,用最小二乘线性回归拟合应力-应变曲线,从而确定了钢绞线的弹性模量,并与机械式引伸计测试结果作比较,结果吻合较好.可见数字图像相关方法为钢绞线的弹性模量检测提供了新途径.

Digital image correlation method（DIC） was employed to measure the elastic modulus of strand wire under tension.Images of the strand wire surface were captured by CCD and corresponding computer system under different loading.DIC was subsequently used to obtain displacement by correlation operation,then the average strain was obtained by fitting the displacement as a plane.The slope of each set of applied stress versus measured strain data was calculated by least-squares linear regression.So the elastic modulus was determined from the slope and compared with the result from extensometer.Both results were in good agreement.Test and analytic results show clear evidence of the feasibility and advantages of DIC in elastic modulus of strand wire measurement,which indicates that DIC is a new approach to test the elastic modulus of strand wire.