INVESTIGATION OF TUBE HYDROFORMING PROCESS ENVELOPE FOR MACRO/MESO SCALABILITY

摘要

The process of tube hydroforming (THF) requires tube stock to be internally pressurized and possibly axially fed inside a die cavity in which the tube plastically deforms to fill the cavity. The purpose (of this investigation) is to explore the impact of the tube geometry, diameter and wall thickness, on the formability of a part. Knowing how the scale of the tube influences formability should allow projections on the performance at the meso forming scale. The most common type of failure is tube wall nominal thickness reduction in excess of 20%. Reductions greater than 20% are deemed more likely for rupture and buckling due to axial forces. Tribological properties are also investigated to determine the impact of friction coefficients on the thinning of the tube wall. The friction impact on the forming dictates the lubrication requirements of the THF process. Process modeling simulations using the finite element method (FEM) are conducted analyze the effect of the various parameters that limit THF processes. Scaling the simulation for meso forming indicates promising results. The macro analysis indicates the tube is capable of being formed at smaller scale.