Fiber-waviness Model in Filament Winding Process

Abstract

Abstract Fiber waviness is one of the initial defects in the filament winding process, and causes reduction of compressive strength of the composite structure. The mechanism of growth of fiber waviness is, however, not completely clear. In the present study, a model for generating fiber waviness is proposed. It is assumed to be due to local fiber micro-buckling arising from the compression load caused by shrinkage of a metal jig. Three faults are considered as causes of micro-buckling: bonding between metal jig and composite, insufficient cure of the resin, and initial deflection of fibers. Analysis and experiments based on this model have been carried out. Key words : Carbon Fibers; Polymer-matrix Composite, Filament Winding, Fiber Waviness, Curing Defects 1. Introduction Although applications of fiber reinforced composites (FRP) are increasing for aerospace structural components because of their high specific strength and stiffness, FRP is not widely accepted for other structures. One of the reasons is difficulty of processing FRP: many trial and error approaches are indispensable for preventing initial defects. Fiber waviness is one of the important initial defects in the filament winding process, and causes large reduction of the compressive strength of composite structures