🪢 Twisted Grass Rope: Lay Angle, Strength Efficiency and Fibre Friction (2D)

Side view of a rope made of two to six helical strands, as in the woven grass cables of the Andean Q'eswachaka bridge. Change the lay angle, the fibre length, the fibre friction and the load, and see how twist locks short fibres together but tilts the strands away from the load. The strand strain, the axial stiffness, the untwisting torque and the lay angle that gives the strongest rope are computed, with four in-page numerical checks.