TPT March 2008

Up to version 2007, Copra ® FEA RF worked without friction and rolls were not rotating. This has advantages for the estimation of the quality of the design itself, but it did not take into account design elements like a step up of the root diameter, and longitudinal elongation or hole deflection of the strip caused by different speeds. With Copra ® FEA RF 2009 it is now possible to automatically build an FEA model with rotating rolls and friction. Using the software, it is possible to easily input the machine’s speed settings, which fi Figure of model with friction/rotating rolls. This model includes driven rolls at specific rotational speed (purple arrowed), idler rotating rolls, driven by speed of the sheet (green striped), deactivating of welding addition and welding, and drawing die (with friction) for improved forming process

calibration stations. This is carried out by the use of contact pressure by arrows. The weld process can also be calculated for unsymmetrical sections and use of more than one processor. Unsymmetrical welding can also be calculated with or without taking into account the weld addition. A restart is now possible during the simulation of the calibration stations (eg in round-to-shape), and also when started from the round tube. This version includes an IGES and DXF interface to export the results of a simulation to, for instance, Inventor or AutoCAD. The complete 3D deformed sheet is exported. The design of a cage can be undertaken very easily, with results automatically prepared for simulation. In addition to optimising tube forming quality, the simulation helps to optimize other factors (eg downhill and cage-mill-settings). data M will also present an interface for SolidWorks. It allows the transfer of a roll design directly into SolidWorks where it can be completed (eg by adding the stations, tool holders for accessory rolls or similar extra equipment).

include driven/non-driven axis, rotational speed (for driven axis), gear ratio, and frictional behaviour. Also possible is the investigation of the elongation of the tube during forming and calibration (eg due to step-up of roll diameter). It also possible to investigate the difference in behaviour between driven top and bottom roll or driven only bottom roll. The software is used to show the pulling and/or braking behaviour of driven stations. The simulation displays if the profile will ‘get stuck’, whether there are any defects, and the braking behaviour of non-driven stations. Furthermore, it investigates the line speed as a function of the rotational speed and friction settings, rotational speed of the non-driven axis, and the driving torque of the driven axis. Calculating a simulation with rotating rolls and friction is especially interesting for thin wall tubing. It makes a difference if one station is pushing too much and the continuous tension is not guaranteed over the complete line. Investigation of pressure distribution is also possible (eg for breakdown or idler stations), especially in the fin stations and

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Diamil srl Design, production and customer service: the best choice for scarfing inserts and tools.

Hall 13 Stand A51

Coated external scarfing inserts

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● Uncoated and coated cutting rings for internal scarfing

Tube chamfering inserts

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● Tools for internal and external tube scarfing

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M arch 2008

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