Investigation of the Thickness Effects on Three‐Dimensional Fracture Toughness in Metallic Materials via the Phase‐Field Model

ABSTRACT With the wide application of large wall‐thickness metallic structures in engineering, there has been a growing focus on the three‐dimensional fracture issues associated with these materials. This article uses the phase‐field model to investigate the impact of thickness on elastic–plastic metallic materials. Initially, the fracture toughness of metallic materials in three dimensions is calculated under elastic deformation. The findings reveal that the outcomes obtained from the phase‐field model remain consistent regardless of thickness, thus confirming its effectiveness. Subsequently, the study delves into the three‐dimensional fracture behavior of metallic materials during plastic deformation. It illustrates how the phase–field model approach enables a thorough simulation of crack propagation within these materials, offering a comprehensive understanding of their fracture behavior. By analyzing the phase‐field contour, the thickness effects of three‐point bending specimens during crack growth are effectively captured. In addition, the dimensionless fracture toughness ratio trends with thickness are compared between phase‐field modeling and experimental results in the open literature, showing good agreement.