A Generalized Ductile Phase Field Model for Fracture Behavior of Three-Dimensional Metal Structures

The commercial finite element software is usually used to analyze the failure modes of metal structures. In this work, we present a generalized ductile phase field model to solve the fracture problems of three-dimensional metal structures. This model can be easily implemented in Abaqus software. The isotropic hardening model and exponential hardening law were used to describe plastic behavior of metals. The different element types were introduced to mesh the structures conveniently. The ductile phase field governing equations were given and solved by the Broyden-Fletcher-Goldfarb-Shanno (BFGS) quasi-Newton monolithic algorithm. Moreover, an efficient and accurate adaptive analytic method of the third-order real symmetric matrix was proposed to implement the tension-compression decomposition. Some typical specimens commonly used in engineering were designed and manufactured. The corresponding static and fatigue tests were carried out, and the simulation results were compared with the experimental ones. The proposed model can predict the crack initiation and propagation of arbitrary three-dimensional metal structures under tensile, shear, torsional and fatigue loading.