Software speeds tape layer production, optimizes precision

As readers of HPC well know, the size and complexity of composite aerospace structures has increased exponentially over the past decade, thanks in large part to automated manufacturing machinery, including automated fiber placement (AFP) and tape laying (ATL) equipment, and the merging of many types of technologies. Prime examples of this phenomenon are the massive fuselage barrel sections produced for The Boeing Co.’s (Chicago, Ill.) new midsized passenger jet, the 787 Dreamliner. But to produce such complicated parts quickly and accurately, those machines need sophisticated computerized control systems that can direct them to lay down composite materials in a very precise fashion, with the fewest pauses or delays and minimal postcure machining.

Toward that end, the Siemens Aerospace Center of Excellence (Elk Grove Village, Ill.) developed the Siemens SINUMERIK 840D, a complex computer numerical control (CNC) system, offering innovative features that, the company claims, can optimize productivity on the manufacturing floor — especially for AFP and ATL. Working in partnership with Boeing and the machine supplier, Siemens installed the SINUMERIK 840D on a large ATL machine, early on, at the former Boeing Wichita plant (now Spirit AeroSystems) in Wichita, Kan.

Since then, the system has enabled production of 787 fuselage components. It does so by acting as the master control for the machine tool and all ancillary devices, including any robotics, in multiple axes of motion. Its open architecture allows customized computer-aided manufacturing (CAM) software programs, typically developed by the machine’s manufacturer, to work in concert with the system to control specific functions, such as composite material laydown and creel system management. Siemens’ controller includes functions that synchronize the CAM parts program with motion control and position control to produce precise cuts and adds, even at high laying speeds, resulting in very clean laying edges. It also includes a virtual NC kernel (VNCK) that allows the real-time control software to be run on a Windows platform, without any CNC hardware, as a plug-in to conventional simulation systems, enabling a realistic simulation of all the CNC functions prior to actual production.