3D DEM-FEM coupling simulation for enhanced deformation prediction in hot isostatic pressing of a complex-shaped component

Hot isostatic pressing (HIP) is a manufacturing technique widely used in aerospace and other fields that applies high temperature and pressure to metal powders to achieve near-net-shape parts with large and complex structures. While numerical simulations such as the finite element method (FEM) can predict forming deviations, the non-uniform shrinkage of powders during the process requires further improvements to existing FEM models to accurately reflect the discrete nature and uneven distribution of particles. To address this issue, a new modelling approach has been developed that couples the discrete element method (DEM) with FEM by integrating local density data into the FEM model. The DEM model was first calibrated and validated by comparing with experimental results, and then used to simulate the filling and vibration of particles in the capsule of a Ti 2 AlNb part. The relative density distribution of particles in different regions of the DEM model was extracted. Subsequently, a Python script was developed to facilitate the automated assignment of these relative density data to the corresponding regions in the FEM model. The initial relative density distribution of powder material in the FEM model not only influenced the evolution of Young's modulus during deformation but also determined the final shrinkage extent of the component. The results demonstrated that the coupled DEM-FEM approach achieved a 45 % reduction in average deviation and notable improvements in dimensional accuracy at multiple characteristic positions, with a maximum improvement reaching 0.585 mm. This DEM-FEM coupling model represents a viable technique for HIP manufacturing processes and can be implemented for components with arbitrary designed geometries.