A 3D rigid–viscoplastic FEM simulation of compressor blade isothermal forging

Based on the rigid–viscoplastic principle, three-dimensional finite element simulation using the penalty function was performed for the isothermal forging of a compressor blade. The key technologies of 3D rigid–viscoplastic FEM simulation are introduced. The workpiece was discretized into eight-node hexahedral isoparameteric elements and the die cavity was discretized into triangular elements. The methods proposed by the authors to remesh the distorted mesh system and to modify a node touching the die have been used. By means of 3D FEM simulation of the compressor blade, the initial and deformed configurations, the deformed meshes of typical cross-sections, the contours of effective strain at the final stage, the vertical load–displacement curve for the upper die, and the horizontal load–displacement curves for the upper and lower dies have been obtained, and so the deformation law of compressor blade forging has been obtained. The research results show that the 3D rigid–viscoplastic FEM simulation system developed in this paper is practical and reliable. In the present simulation, the tenon and the body on the blade die cavity are joined by an arc which coordinates the deformation between the tenon and the body, and friction is considered along the interface between the die and the workpiece. Thus, this simulation approaches practical compressor blade forging. The computational results can also be applied effectively to other types of blade forging processes.