Mechanical Properties of Flexible Structures with Helical Reinforcements under Axial Load

Abstract

Flexible structures with helical reinforcements are widely used in engineering because of their low bending stiffness and high strength. To strengthen the core, we focus on those structures which the helixes will contact the inner core loaded axial tension. The contact pressure between layers is taken into consideration and eliminated by using deformation compatibility equation. The pitch angle changes under axial tension which induces the geometric nonlinearity. The results were systematically compared with other researchers’ theory, which adopted more assumptions. Suggestions about the appropriate range of parameters are given, when assumptions can be used. The solution is validated with that obtained by both the finite element method and the classical solutions of two extreme cases.