Modeling and Analysis of Variable Parameters for Compound Hole Expansion of Fit Bushing

A three-dimensional finite-element model was generated of the hole expansion of a fit bushing for an aerospace aluminum alloy lug with a hole, and the effect of the compound hole expansion treatment in which the hole wall and the bushing are both extruded was investigated. Results show that the main technical advantage of compound hole expansion (CHE) lies in the subdivision of the strengthening effect on the bushing and hole parts, which in turn reduces the requirements of the composite processing technology on the extrusion equipment; under certain conditions, both the bushing and the hole parts have weaker strengthening effects if the selected interferences in the two stages of the CHE processing are both low.