Pucker, wrinkle, bridging
Three defects where the tow leaves the surface, all from a length mismatch between the tow and the path it has to follow. Steer a tow of width w around a radius R and its edges want different lengths: the inner edge is w/(2R) too long, the outer w/(2R) too short. Carbon hardly stretches, so the outer edge pulls tight and the inner edge buckles: wrinkles.
Predict · at 0:52 in the video
Try it. A quarter-inch tow, steered at a five-hundred-millimetre radius. Per metre of path, how much longer is the outer edge than the inner?
About thirteen millimetres. The width over the radius: one point two seven percent. Each edge is off by half that.
Automated Fiber Placement: Status, Challenges, and Evolution, Ramy Harik & Alex Brasington.
- Chapter 3, section 2.3
- Chapter 3, section 2.2
- Chapter 3, section 2.4
Simulations in this lesson are our own. Where the numbers are invented to show a mechanism, the video says so on screen.
