Research on Identification of the Plasticity Parameters of X80 Steel Based on Dimensional Analysis and Kriging Modeling Method

Abstract

Abstract. Traditional tensile tests are not suitable for evaluating the mechanical properties of in-service pipelines, while indentation testing provides a more convenient alternative due to its minimal damage and effectiveness in characterizing material properties. To address the challenge that indentation tests require extensive numerical calculations, this paper proposes a method that combines dimensional analysis with Kriging modeling and solves for X80 plasticity parameters using the Nondominated Sorting Genetic Algorithm II (NSGA-II) algorithm. The approach begins with optimal Latin hypercube sampling to gather data, followed by obtaining initial sample results through a finite element model, which is then used to train the Kriging model. Finally, the NSGA-II algorithm is applied to solve for the X80 plasticity parameters. Three additional materials were tested for validation. The results indicate that, compared to uniaxial tensile tests, the errors in initial yield strength and hardening index for X80 are both within 5%. Moreover, compared to traditional numerical simulation methods, this approach requires fewer finite element simulation samples, thereby improving solution efficiency. For the remaining materials within the sample space, errors remain within 10%, demonstrating that this method holds substantial practical value in engineering applications.