2017 Volume 43 Issue 6 Pages 234-243
Discontinuities in a particular pattern are introduced into a unidirectional prepreg to improve flowability while maintaining desirable mechanical properties. In the compression molding of this unidirectional discontinuous prepreg, discontinuities in a certain pattern appear, but it is difficult for finite element methods to simulate the appearance of discontinuities because constitutive laws between nodes around discontinuities are unknown. In response, we developed a method to simulate the compression molding of unidirectional discontinuous prepreg based on the Moving Particle Semi-implicit method. Particle methods are preferable to simulate this phenomenon because they do not use mesh and particles can move freely. To represent the unidirectional discontinuous prepreg, the particles were connected as fiber bundles separated by discontinuities and forces worked in/between bundles. The present method can simulate differences in the shape of discontinuities according to the patterns. And the following conclusions could be drawn: (1) The shape of discontinuities depends on the geometric position of discontinuities and the flow perpendicular to fiber direction. (2) The oblique pattern has better geometric adaptability in response to local shape change than the orthogonal pattern. (3) In compression molding, the laminate part near the edge flows farther than the laminate part around the center.
