Welded joint creep deformation prediction method based on DIC technology

The invention discloses a welded joint creep deformation prediction method based on DIC technology. The method comprises the following steps of S1, processing a welded joint sample; s2, applying a constant loading stress level to the sample, and measuring axial strain field data of the sample at a plurality of discrete moments by using the DIC technology; s3, extracting creep axial strain values of a base material, a weld joint and a welding heat affected zone; s4, changing the loading stress level of the creep test, and repeating the steps S2-S3 to obtain a creep axial strain data pair; s5, constructing a material creep constitutive model, fitting the obtained creep axial strain data pair into the creep constitutive model, and respectively obtaining optimal estimations for creep constitutive model parameters of the base material, the weld joint and the welding heat affected zone; and S6, substituting the creep constitutive model parameters into the creep constitutive model, and predicting creep deformation of the base material, the weld joint and the welding heat affected zone of the welded joint under different stress levels. The method realizes simultaneous characterization andprediction of creep deformation of different areas of a real welding joint.