JEC COMPOSITES MAGAZINE - Issue #122 - July 2018 - 63

simulation TECHNOLOGY

Optimizing the key manufacturing
parameters of the AFP process

lei shi,
Software Research and
Development Co. Ltd.
Autodesk (China)

Most users of Automated Fibre Placement (AFP) equipment use the software
provided by the machine vendor, which is simply not economical or realistic for
manufacturers. This paper presents a universal AFP software program (Autodesk
TruFiber) that allows manufacturers to select the best machine for the job.
Additionally, case studies are used to expound the optimization of the kinematics
parameters of the AFP process.

xperimental studies [1] proved the necessity of upgrading
manufacturing systems with simulation tools. A previous study [2] focused on the statistical data required to
evaluate the impact of various design concepts against various manufacturing processes. Autodesk TruPlan is based on
multiple advanced optimization algorithms and assesses the
cost impact of unique design features and surface definitions
across multiple manufacturing processes such as Automated
Fibre Placement (AFP), Automated Tape Laying (ATL),
Hand Lay-up (HLU) or any combinations of these strategies.
It was proven that conducting a manufacturing feasibility
analysis makes it possible to catch common fabrication issues
at an early stage.
Down to the manufacturing stage, however, most AFP equipment users still use the software provided by the machine vendor. Such software developed for one specific machine brand
is only used by a small set of users and limited to the requirements of that specific machine, which is simply not economical or realistic for manufacturers.
Autodesk TruFiber is designed to support composite manufacturing processes such as AFP and ATL using data from
Autodesk TruPlan, allowing the management of multiple processes and the generation of tool paths with the associated NC
codes for manufacturing. In this paper, major manufacturing
parameters are taken into consideration in discussing the optimization from a safety, accuracy and efficiency point of view.
Kinematics optimization
The fibre placement operation is not straightforward to interpret, even if the design information was well collected, since it
depends on a number of factors such as the tow laying direc-

tion, the off-part motion, the compacting pressure of the AFP
roller and the feed rates of the machine head.
In this section, several kinematics parameters are discussetd
to improve production efficiency, reduce material costs and
save time.
Operation strategy
Layup direction: Typically, two types of machine movements
need to be eliminated for higher fabrication efficiency: offpart motion and head reversing motion. For small parts, a unidirectional layup (as shown in Figure 1 (a)) is recommended
as the head rotation is much more time-consuming. For large
parts, however, the off-part motion becomes a major concern
due to the long linking path, so the bidirectional strategy (as
shown in Figure 1 (b)) is a preferable choice to reverse the
machine head after completing each fibre course. TruFiber
provides an optimal "combined" solution to recommend the
"Maximum unidirectional length", meaning that any course
shorter than the defined value is not reversed, otherwise it
goes in a bidirectional way. Figure 1 (c) shows the tool paths
computed using the "combined" layup strategy, where the
"Maximum unidirectional length" is set to 1000 mm.

Fig. 1: Tool path results computed with three types of layup direction strategies
on the same circle-diamond-square part: (a) unidirectional layup, (b) bidirectional
layup and (c) bidirectional with "Maximum unidirectional length"

N°122 July 2018

/ jec composites magazine

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #122 - July 2018