The hydraulic tube bulging of a tube-attached lining rubber membrane with axial compressive force.

Abstract

The authors have developed a new machine for tube bulging which initially puts a deflated rubber membrane into a work tube and drives the internal pressure through a membrane after the initial settingup. Using this new machine, the effects of the tube end condition and tube length on the deformed shaped and the strain distribution are examined experimentally. Three cases of the tube end conditions, (A) axially fixed, (B) axially free and (C) axially compressed by force, are parametrically investigated. The results are as follows: (1) comparing at the same bulge height, the internal pressure is lower with the longer tube and also lower with the end condition changing from case A to C, (2) when the tube is short and/or the axial compressive force is small, the deformed shape appears as a barrel, and when the tube is long and/or the axial force is large, it has a cylindrical region uniformly expanded at its center, and (3) the axial compressive force tends to prevent thickness reduction of the tube.