Adaptive modeling of three-dimensional hull structure and simulation of crack extension based on ordinary state-based peridynamics

Traditional continuum mechanics faces challenges in solving discontinuity problems, such as cracks, due to the singularity of derivatives at the crack tip. While peridynamics can simulate spontaneous crack initiation and propagation via integral equations, bond-based peridynamics (BB-PD) is limited by fixed Poisson's ratios (0.25 for 3D, 0.33 for 2D), which limits its practicality for general engineering applications. This study establishes a three-dimensional (3D) crack propagation model for hull structures based on the ordinary state-based peridynamics theory. The specific research contents are as follows: (1) The "1D pre-screening + 3D precise search" algorithm is adopted to realize the fast adaptive modeling of hull structures; (2) combined with the fracture toughness test data of Q235 steel, a highly adaptable crack propagation analysis model is proposed. This model can automatically complete the construction of hull structures and preset cracks and realize the prediction of the whole process of natural crack initiation, propagation, and coalescence.