System and method for determining the direction and spacing of fiber paths for a composite ply

Abstract

A method (100) of determining fibers paths (314) for a composite material layer sheet (202) includes generating a triangulated surface (218) of the composite material layer sheet (202), and defining afirst unit vector field establishing a 0-degree direction (302) for the triangulated surface. A second unit vector field (306) is defined by rotating, through specified fiber angles measured relativeto the 0-degree direction, the first unit vector field about surface normals of the triangulated surface. A third unit vector field representing a gradient direction (308) of a potential function isdefined by rotating the second unit vector field over 90D about the respective surface normals. The third unit vector field is scaled to create a non-unit vector field, and a first potential functionis determined by performing a least-squares fit such that the direction and magnitude of the gradient best approximate the direction and the magnitude of the non-unit vector field. A normalization ofthe potential function uniformly distributes contour lines of the potential function across the triangulated surface. The contour lines are used as fiber paths for laying up courses of composite material to fabricate the composite material layer sheet (202).

Description

technical field [0001] The present disclosure relates generally to composite manufacturing and, more particularly, to systems and methods for determining the direction and spacing of fiber paths for laying up composite tows to form composite plies. Background technique [0002] The design of the composite laminate includes specifying one or more fiber angles for each composite ply in the composite laminate. For example, a structural design engineer may specify fiber angles for each composite ply measured relative to a reference direction on the surface of the composite ply. For visualization and use in computational algorithms such as stress analysis software programs, the fiber angles can be represented by a vector field on the surface of a composite ply. To fabricate composite plies, manufacturing engineers can model fiber angles as continuous fiber paths when programming automated lay-up equipment. For example, an automated fiber placement machine (AFPM) may be programm...

AI Technical Summary

Problems solved by technology

However, for composite plies with curved profiles and / or non-constant fiber angle distributions, fiber paths following the fiber directions specified in the fiber angle distribution may not be parallel to each other

As a result, the courses may converge and / or diverge at certain locations of the composite plies, resulting in overlap and / or gaps between adjacent courses

Overlap and gaps can negatively affect the structural properties (e.g., strength, stiffness), surface quality, and manufacturability of composite laminates

Furthermore, design engineers do not have the ability to consider the effects of convergence and divergence on the manufacturability of composite laminates, which can lead to costly and time-consuming rework of composite laminates during fabrication

Additionally, the inability to account for convergence and divergence during the design phase of composite laminates can mean that more efficient designs are never considered

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