Change in preform thickness throughout the vacuum assisted resin infusion process and the post-filling control

The non-contact electric eddy current displacement sensor system was applied to real-time monitor the preform thickness change throughout the vacuum assisted resin infusion(VARI) process.The compaction behavior of the preform during the VARI process was discussed.And the effect of the post-filling time on the preform thickness and the fiber volume fraction was studied.The result indicates that the compaction behavior of the preform can be divided into three stages: the preform thickness increases rapidly when the resin is infused;the perform thickness is almost not changed during the post-filling;the preform thickness decreases rapidly and drives to a stable value after that the resin-inlet is clamped.The final part thickness varies with the post-filling time,and the variation tendency is similar to a sinusoid.The fiber volume fraction is the lowest and decreases 1.7% compared with that without post-filling,when the post-filling time is about 10 min.And the fiber volume fraction is the greatest and increases 1.6% compared with that without post-filling,when the post filling time is about 40 min.