Rapid cut state detection for carbon fiber composite tow

It is difficult to identify the cut state of fiber tow in a small space. A rapid cut state detection strategy for carbon fiber composite tow is proposed following the electrical signal measurement, and the corresponding cut state detection system is constructed. The electrical signals generating during the process of cutting are collected by a simple circuit and DAQ card, then filtered by low-pass filter to obtain the peak value of the signal. The peak value is compared with the rated threshold of 1 V to identify whether the fiber tow is completely cut off or not. In the experiment, the resistance of fiber tow which is not completely cut off gets 10 to 500 Ω, while the resistance of fiber tow which is completely cut off reaches infinity. Connecting the fiber tow with the electrodes in the circuit, the changed resistance value directly affects the voltage value between both electrodes. When the fiber tow is completely cut off, the voltage increases from 0 to 4.377 03 V, higher than the threshold. When the fiber tow is not completely cut off, the voltage increases from 0 to 0.067 97 V, lower than the threshold. Both of the cut states can be identified effectively and quickly. This detection can be realized in a very small space, even inside the AFP robot head.