Tool Design Software and Simulation of the Wire Rolling Process:
1) COPRA® FEA WR

l Model with driven stations
The software supports the effective design of wire rolling tools and the finite element simulation of the complete wire rolling process.

The starting product for shaped wire is very often round or rectangular wire. Proceeding from this geometry, the wire is turned into the required final form by means of a number of rolling passes. So only the starting and final state of the wire is known. As shaped wires very often have geometries with different radii, the definition of respective intermediate stages is a complex matter.

In addition to the purely geometric aspect, there are some other factors that play a nevertheless important role. These include the fact that the material lengthens when it is formed, and can be very difficult to force into the border regions. Large deformations produce local strain hardening, as a result of which the material can become brittle and thus fissured.

The COPRA® WR (Wire Rolling) solution for wire rolling supports the tool engineer with some important features.

§ One is the interactive modeling of the forming steps - based on experience which is already available: the software calculates and sketches the subsequent forming steps while the designer is able to put respective cross sectional areas into any wanted percentage ratio.

§ COPRA® WR automatically designs the different cross sections of each shaping step. The user just defines the start and end cross-section. He can also specify the degree of forming and the estimated amount of reduction of any cross-section.

§ The final but not least important step in the COPRA® WR process chain is the verification of the design by finite element simulation. Forming is computed based on roller geometry and the starting cross-section.

§ COPRA® FEA WR simulates the wire rolling process by means of the non linear elasto-plastic solver MSC.MARC and provides the user with important information about the final wire shape to be expected. The software allows the prediction of the material properties and thus an optimization of the wire rolling process with regard to its final properties.



picture 1: COPRA_FEA_WR.jpg
COPRA® FEA WR allows the simulation of the wire rolling process

Revised have been the last and nearly the most important points in the process chain and the verification of the design. Up to now, the simulation model was created with all rolls of the same values. This means, that all axes have the same rotation speed and for all rolls the friction value is the same between the wire and the tool.

In reality it is possible that there can be different velocities for the stations, or even idler stations. Because of that the user has the possibility to put in the values for friction and speed in a dialog for each roll or axis.



picture 2: FEA_RF_Friction_Dialog.tif:
Comfortable input of the machine’s speed settings: driven / non-driven axis, rotational speed for driven axis, gear ratio, frictional behaviour

§ Comfortable input of the machine’s speed settings: driven / non-driven axis, rotational speed for driven axis, gear ratio, frictional behaviour, etc
§ Investigation of the elongation of the tube during forming and calibration e.g. due to step up of roll diameter
§ Investigate difference in behaviour between driven top and bottom roll or bottom roll driven only
§ Shows the pulling and or braking behaviour of driven stations. The simulation will show if the profile will “get stuck”.
§ Defects caused by e.g. different positions of the drive diameter will be made visible
§ Check the braking behaviour of non-driven stations
§ Investigate the line speed as a function of the rotational speed and friction settings of the machine
§ Investigate the rotational speed of the non-driven axis
§ Investigate the driving torque of the driven axis
§ Calculating a simulation with rotating rolls and friction is especially interesting for thin wall tubing where it can make a difference if one station is pushing too much and the continuous tension is not guaranteed over the complete line



picture 3: FEA_RF_Transporting_Diameter.tif:
Definition of transporting diameter by comparing forward and backward slip between rolls and profile

l Display of forming forces
Comfortable investigation of distribution of pressure in e.g. breakdown or idler stations but especially also in the fin stations and calibration stations by the use of representing the contact pressure by arrows. Size, colour and direction of the arrow give information about roll pressure over the circumference of the tube.

l Multi-processor ability
For COPRA® FEA RF 2009 two options for parallel processing are available. One is a parallel_2 license allowing calculating one job on 2 processors. This reduces calculation time by up to 40%. The second option is a parallel_4 license reducing the calculation time by up to 65%.

2) COPRA® RollScanner

l High quality tooling for better products!
There are no doubts many advantages of using CAD/CAM software for the layout of wire rolling rolls or roll form tooling. But does the actual geometry really meet the original design of the rolls? Even a minor deviation from the original roll contour may result in minor quality tubes or profiles.
The COPRA® RollScanner is a fully automatic measuring device for inspecting existing rolls of wire rolling mills or roll forming lines quickly and accurately. It satisfies the roll forming industry’s big demand for a high-quality control system.

picture 4: COPRA_RollScanner.jpg
The COPRA® RollScanner - Type 200

l Quality control at a glance: the roll’s “fingerprint”
The COPRA® RollScanner allows the user to register existing rolls and provides continuous quality control. After scanning the roll you will also get an immediate comparison of the measured contour and the originally designed reference contour if available in the COPRA® Database. The deviation is shown in a diagram. All information about the deviation can be exported to MS Excel for further analysis and printout. The typical “fingerprint” of the scanned roll appears on the screen. The deviation is indicated by red crosses.

l Fully automatic scanning and easy to use
The COPRA® RollScanner can be handled very easily without any experience with computers: simply put the rolls on the plug. After entering a roll number or another identifier, the roll is being scanned automatically without any additional programming required. The whole scanning process takes about one minute (depending on roll size). Your digitized actual contour now appears on the screen. The data can be saved in common format, e.g. DXF, and can be processed and stored by nearly any CAD system.

l Get the original forming strategy of stocked rolls
After transferring the scanned data into the COPRA® Database, the original forming sequence (flower pattern) is available and can be used by the designer for new tubes or profiles. With these data the user can now simulate, optimize and draw new roll sets as well as generate NC files as if he had designed his own rolls.