Prediction Method for Cable Tangling Could Aid in Underwater Fiber Optics

When sending an email, it travels through submarine optical cables that had to be installed at some point. The positioning of these cables can generate intriguing coiling patterns that can also cause problems if, for instance, they are tangled or kinked. The deployment of a rodlike structure onto a moving substrate is commonly found in a variety of engineering applications, like the laying of submarine cables and pipelines, and engineers have long been interested in predicting the mechanics of filamentary structures and the coiling process. Now, mechanical engineers at MIT have collaborated with computer scientists at Columbia University and developed a method that predicts the pattern of coils and tangles that a cable may form when deployed onto a rigid surface. They discovered that in particular, the natural curvature of the rod dramatically affects the coiling process. The research combined laboratory experiments with custom-designed cables, computer-graphics technology used to animate hair in movies, and theoretical analyses.

Transcript

00:00:05 Engineers at MIT along with computer scientists at Columbia University have developed a method that predicts the pattern of coils and tangles that a cable may form when deployed on a rigid surface. They say the method may help to design better strategies for deploying underwater fiber-optic cables. In the lab, MIT engineers set up a desktop system to spool spagetti-like cables onto a conveyer belt.

00:00:33 They adjusted perimeters such as speed of deployment and the speed of the belt and observed how the cable coiled as it hit the surface. The patterns created in the lab were successfully predicted using an adapted code, originally developed to animate hair and cloth. The researchers say the coil-predicting method may help design better deployment

00:02:42 strategies for fiber-optic cables to avoid twisting and tangling that could lead to transmission glitches. In the future the researchers hope to explore the mechanics of a large group of thin, elastic rods such as a full head of hair. They are working to accurately simulate friction, contact and collisions between individual hairs.