Stress Development in Wet Filament Wound Pipes

Abstract

A computer based process model for wet filament winding has been developed. A software supplied by Stanford University has been modified for the numerical simulation. The model has been verified with manufacturing of glass fiber pipes including the industrially common case of pipes with mixed angle lay-up. Resin pressure in the composite during winding was measured and found to be relatively low supporting the assumption that it can be neglected for this process. Calculated final fiber fraction distribution agrees well with measured values on cured pipes. The model shows that fiber fraction is changed significantly during the winding stage due to compression forces. Mechanical and total strain measurements generally show good agreement with calculations. Analysis of ring gaps indicate that residual stresses are dominated by other effects than matrix shrinkage for the investigated parameter combination.