双金属复合管残余应力测试方法研究

Study on Measurement Method for Residual Stress of Bimetallic Composite Pipe

以双金属复合管的基管为研究对象,将数字图像相关方法和盲孔法结合分析其残余应力分布规律.结果表明:双金属复合管的基管外壁在圆周方向和轴向方向的残余应力均为拉应力;圆周方向和轴向方向的最大残余应力分别为252.68 MPa和241.16 MPa,标准差为5.18 MPa和4.54 MPa;圆周方向和轴向方向的最小残余应力分别为105.56 MPa和113.96 MPa,标准差为2.68 MPa和3.41 MPa.通过数字图像相关方法结合盲孔法能够准确测量双金属复合管基管外壁残余应力,满足工程测试要求.

The base pipe of the bimetallic c omposite pipe is taken as the research object,and the digital image correlation(DIC)method and the blind hole method are combined,and used to measure its residual stress distribution law.The results show that the residual stresses in the circumferential and axial directions in the outer wall of the base pipe of the bimetallic composite pipe are tensile stresses.The maximum residual stresses in the circumferential and the axial directions are separately 252.68 MPa and 241.16 MPa;the standard deviations are 5.18 MPa and 4.54 MPa.The minimum residual stresses in the said two directions are seperately 105.56 MPa and 113.96 MPa;the standard deviations are 2.68 MPa and 3.41 MPa.It is proved that the residual stress of the outer wall of the base pipe of the bimetallic composite pipe can be measured accurately by means of using the DIC method together with the bind hole method so as to meet the requirement for the engineering measurement.