Automatic Fibre Placement for Local Winding
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Introduction
The mechanical efficiency of COPVs (pressure vessels) can be often be improved by using a hybrid process of filament winding and localised reinforcement using an Automatic Fibre Placement (AFP) methods. There is an article discussion this in detail by following this link
AFP local reinforcements can be created by the create fibre path from the main menu/ option via the friction/step dialog. You can start the path at any position and angle and finish at any position/angle. The fragment of path will be replicated around the mandrel with a set of bands for the positive wind angle and a set of bands for the negative wind angle. To differentiate this type of path from a normal fibre path the .fib file must be tagged by selecting the AFP menu option on the friction/step dialog. This pops the custom dialog shown below which has some parameters that must to be defined. These that get saved withing the .fib/.pay files
The band width and tape thickness (t0) need to be set if they are not already set, the free fibre length is the tangential distance from the mandrel surface to the tape placement roller. This is in effect zero but we advise a small positive value like 1mm or 0.1mm. The AFP standoff clearance is a distance the tape head retracts normal to the mandrel surface at the end of the path before repositioning to the start of the next segments and then moving in a normal direction back to the mandrel surface. When the payout paths are calculated a .th2 thickness/angle file for use with FEA models is created. This .th2 is for both the positive angle band set and the negative angle band set but these are created as separate .pay files.