Finite element numerical simulation of 4-roll plate rolling process

In the last article, we covered: The 6 Steps Of The Plate Rolling Process Of The 4-Roll Plate Rolling Machine.
In this paper, finite element software is used to numerically simulate the coiling process of a certain type of 4-roll plate rolling machine.

ABAQUS is generally considered to be the most powerful finite element software. It is a structural mechanics system capable of analyzing complex solid mechanics, especially capable of handling very large and complex problems and simulating highly nonlinear problems. Here we use the dynamic explicit algorithm to analyze the sheet rolling process of the 4-roll plate rolling machine. Read More: ABAQUS wikipedia

Model establishment of a 4-roll plate rolling machine

According to the structural characteristics of the 4-roll plate rolling machine, the force change of the plate in the width direction is very small. At the same time, in order to reduce the calculation time, the bending forming of the plate can be regarded as a two-dimensional plane for simulation calculation. The diameter of the upper roller of this model of a 4-roll plate roller is Φ950 mm, the diameter of the lower roller is Φ900 mm, the diameter of the left and right rollers is Φ700 mm; the length of the metal plate is 8000 mm, the width is 2400 mm, and the thickness is 60 mm.

Mechanical properties of metal plate model materials

During the metal plate rolling process, the deformation of the rollers of plate roller is much smaller than that of the sheet. Therefore, all rollers in this model of a 4-roll plate rolling machine are set as rigid members. The metal plate is made of Q345R with a density of 7800 kg/m3, an elastic modulus of 210 GPa, and a mooring ratio of 0.3.

Simulate the four-roll coil test process

According to the actual situation of the bending of the plate, set the upper roller and the upper surface of the plate, the lower roller and the lower surface of the plate are in surface contact, and the friction coefficient is set to 0.5; the left and right rollers and the support roller are in surface contact with the lower surface of the plate , the friction coefficient is set to 0.2, the main surface is selected on the outer surface of the roller, and the secondary surface is selected on the upper and lower surfaces of the plate.

Read More: Plate Rolling Process, Basics of Sheet Metal Rolling, Plate Rolling Formula,2 Tips and 11 Key Points for Plate Rolling

6 steps of test process

The four-roller plate bending machine mainly adjusts the bending diameter of the plate by controlling the different displacements of the side rolls rising. Therefore, the displacement loading method is used in the analysis process. Since the rollers are set up as rigid bodies, the boundary conditions and loads act on the reference point RP, which exerts gravity on the sheet. The simulation process is divided into the following steps:

• The lower roller moves up 339.2 mm to clamp the sheet;
• The right roller moves 460 mm to the pre-bending position;
• The upper and lower rollers rotate at a given angular speed to perform end pre-bending;
• The falling displacement of the right roller is 126.7 mm, so that its upper axis is parallel to the upper axis of the lower roller;
• The left roller moves 300 mm to the coiling position;
• The upper and lower rolls rotate at a given angular speed for continuous rolling.

In the process of applying the load, in order to reduce the real stress wave generated, the amplitude curve should be as smooth as possible, which is defined by smooth step in this paper.

Simulation results

It can be seen from the Mises stress cloud diagram obtained after simulating sheet forming that the rolling effect is better. Since the influence of plate spring back on a plate rolling is not considered in the simulation calculation in this paper, the simulated result is slightly smaller than the bending radius of the plate in actual production. Through the query function of the post-processing software, the coordinates of several nodes on the inner diameter of the formed plate are selected, and the inner diameter of the formed plate is Φ1127 mm through fitting. The inner diameter of the pre-rolled sheet calculated by the empirical formula without considering the springback deformation is Φ1105 mm, and the error between the two is not more than 2%, which shows that the established model of the sheet bending forming of the 4-roll plate rolling machine is basically correct.

Summarize

The finite element analysis software ABQUS/Explicit is used to simulate the forming process of the plate of the four-roll plate rolling machine, and according to the simulation results, the experimental study of the plate forming is carried out. The results show that the established plate bending finite element model is correct and can be effectively Simulating the forming process of plate bending has guiding significance for the production practice of the four-roller plate bending machine.

Next Article: Example Of Plate Rolling Process Of Four Roll Plate Rolling Machine

Works CIted: Research on the plate rolling process of 4-roll plate rolling machine