Size effect related wall thinning of thin-walled CP-Ti tubes in rotary draw bending

The study aims to identify the influences of the tube geometries (including out diameter D and wall thickness t) to the wall thinning of the thin-walled CP-Ti tubes in RDB. The mechanical properties of four types of thin-wall CP-Ti tubes are obtained by the uniaxial tensile test, and a series of 3D-FE models are established and validated. By means of analyzing the wall thinning degree at the extrados, the size effect related wall thinning of thin-walled CP-Ti tubes are investigated. The study shows that: 1) The material property variation has obvious effect on the wall thinning of the thin-walled CP-Ti tubes, and the larger the work hardening exponent, the smaller and more uniform of the wall thinning. 2) The effect of the out diameter on wall thinning is complicated in RDB of thin-walled CP-Ti tubes, and at a specific range, the wall thinning has a decreasing tendency with the increasing of the out diameter. 3) The wall thinning decreases with the increase of the wall thickness, and the larger the wall thickness, the larger the decreasing tendency.