Figure 9 shows the PEEQ distribution of rolled ring at different rolling times (PEEQ stands for the equivalent plastic strain).
Figure 9(c) shows that, with the increase of rolling time, the wall thickness of UPR and LPR became thinner at the second forming stage, while the PEEQ at both the inner and the outer surfaces of the rolled ring became larger.
Since the PEEQ and temperature distributions of the inner L-shape ring are axis-symmetric about its center, a certain cross section of rolled L-shape ring "S-S" is selected to study the PEEQ and temperature distributions at t = 125 s, as shown in Figures 10(b) and 10(c).
In Figure 10(b), ten points (from point A to point J) were selected to investigate the change laws of the PEEQ of the rolled ring with rolling time.
Moreover, it can be seen that the PEEQ at point F increases fast at the first forming stage and then increases slowly at the second forming stage.
 investigated the effects of rolling parameters on PEEQ and temperature distributions in radial-axial ring rolling process and declared that, with the increase of the mandrel feed rate and the initial temperature of ring blank, the PEEQ and temperature distributions of rolled ring become more uniform.
However, reports about the PEEQ and temperature distributions in profiled ring rolling processes were insufficient, especially those about conical ring rolling process.
Therefore, it is significantly necessary to set up the FE model of conical ring rolling process, establish the plastic penetration condition and biting-in condition in rolling process, deduce a reasonable mandrel feeding strategy, and investigate the effects of key forming parameters on the PEEQ and temperature distributions of rolled rings, average rolling force, and average rolling moment.
The effects of ring's outer radius growth rate and the sizes of rolls on the uniformity of PEEQ and temperature distributions of rolled rings, average rolling force, and average rolling moment were analyzed.
Investigate the changing laws of the PEEQ and temperature distributions with rolling time.
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research was funded by the Texas Education Agency through the Project for Educator Effectiveness and Quality (PEEQ
) at the Center for Health and Social Policy at the University of Texas at Austin.
As this figure shows, PEEQ
strains are more uniformly distributed between multivoids, such that the normalized PEEQ
(plastic equivalent strain divided by yield strain) at the most critical location of a connection (i.e., at the root of weld access hole) reduced from 92.77 for the beam with single pair of voids to 46.01 for multivoid specimen.