Mathematic modeling and CAD of complicated round helical structure during coiling around drum or pulley

In order to master the structure of complicated round helical structure such as electric cable, rope, mathematic expressions of components' path of round helical structure during coiling around a drum or a pulley were deduced and the method of CAD was discussed. Depending on explicit expressions of components' path, the complicated forms such as double, triple and more complicated structure during coiling around a drum or a pulley could be depicted and the three-dimensional shapes of components were described by taking the software Pro/Engineer. For evaluating components' stresses of helical structure during coiling around a drum or a pulley in future, curvature, torsion of double components and their variance were investigated. The method about mathematic modeling and CAD of complicated round helical structure during coiling was investigated, which favor to compile program of design complicated round helical structure and master the stress and deformation during laying or coiling.