Controlled, Stable Processes
The composite manufacture of aircraft parts requires an integrated, tailored process chain. The CNC functionality of the Sinumerik 840D from Siemens Industry guarantees controlled, stable processes.
Posted: April 5, 2013
High-Performance CNC Functions…
Different requirements are placed on the CNC for the building processes of tape laying and fiber placement, compared with conventional cutting applications.
To coordinate cutting control and motion control in the best possible way for fiber placement, the Sinumerik 840D from Siemens Industry, Inc. (Elk Grove Village, IL) offers synchronizing functions controlled according to actual positions, which synchronize the switch actions of the user or parts program with the motion control and position control.
As a result, all the cuts “sit” precisely in their target positions, even at high laying speeds, which produces very clean laying edges.
High-performance transformation functions are also integrated in the Sinumerik 840D, which makes it possible for workpiece coordinates to be programmed. This makes the part programs, in principle, independent from the machine kinematics and also improves clarity and the maintainability of the part programs.
Even if an accurate axis-parallel mounting of the mold is not possible, due to the size and weight of the mandrel, high-performance transformation functions guarantee the synchronous programming of the laying head movements and of the mandrel, as well as the appropriate alignment of the laying roller.
It is necessary that these structures be designed for genuine five-axis operation or, as is the case with fiber placement, for at least six or seven synchronous axes of motion.
… and Cycles for High Quality
The advanced CNC on these and other production machines must also support composite material prep with special cycles for composite drilling and other lightweight construction materials for laser and waterjet cutting and for many other operations.
High-performance open interfaces enable seamless logging of the actual values for all the process-relevant parameters and machine data for quality assessment. Here again, programming the workpiece coordinates is a key factor, in order to utilize the results of an automated material test with very little effort, or even automatically for process optimization.
Realistic Process Simulation
In order to precisely simulate the time-consuming production of large and complex aircraft components, not just geometrically, but also technologically – including all process-relevant machine properties – the Sinumerik 840D CNC has a virtual NC kernel (VNCK) onboard.
The real-time control software can be run on a Windows platform without any CNC hardware and enables a realistic simulation of all the CNC functions as a plug-in to conventional simulation systems. The production machine’s data are also applied here.
This means that the use of the simulation is no longer restricted only to the pure test of the part programs generated in the CAD/CAM system, but also enables an optimization of both the part program and the major process parameters.
Controlled, stable processes, which lead to optimum results, are an essential prerequisite in economic aircraft construction with a high proportion of composite components. This is the main reason many of the supply system partners in the aerospace industry prefer to rely on CNC machine automation solutions. www.usa.siemens.com/motioncontrol, SiemensMTBUMarCom.sea@siemens.com
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