Integral forming for special-shaped curved surface shell parts of turbofan engine

The special-shape curved surface shell parts of turbofan engine, which vary greatly in diameter, are usually manufactured by forming decomposed parts and then assembling them through welding. The traditional forming technology has some disadvantages, such as requirement of multi-forming-step, high cost and low accuracy, which can be overcome by viscous pressure integral forming process. Through numerical simulation and experiments, the effects of forming steps and the tangent adhesive stress of viscous medium on the material flow and wall thickness variation are analyzed. Research results show that the deformed sheet metal flow can be controlled efficiently and the homogeneity of wall-thickness of formed part is improved through viscous pressure forming (VPF). The wall-thickness thinning is less than 12% for the parts with 1.38 diameter ratio. So VPF is very suitable for integral forming of the special-shape curved surface shell parts of turbofan engine.