Development of a new device for single fiber fragmentation tests

A new device for single fiber fragmentation tests was developed. The image acquisition and motion control systems were constructed based on programmable logic controller technique and a servo system. The software for the real-time acquisition, display, and stitching of fiber images were self-developed and realized by using multi-task and multi-thread parallel processing technique in LabVIEW. A fast image stitching algorithm was adopted which uses edge information for the selection of base feature block and improves the speed by employing a hierarchical search strategy. From the edge and feature extraction, the diameter and fragmentation characteristic length of the fiber in specimen were derived for computing the interfacial shear strength, an important evaluation index of the mechanical performance for composites. Cooperated with a conventional universal material testing machine, the trial test demonstrates that the new device can ensure a good test precision and repeatability with a much lower cost.