Stress distributions on the cross-section of the rectangular prism (left) and of the bare helix model without backbone stiffness (right).

(a) Three-dimensional structures, (b) the axial stresses under tension, (c) the axial stresses under bending, and (d) the in-plane shear stresses under torsion. Results are calculated using E_c = 668 MPa, D = 2.4 nm, and 1/AR = 0.6 with the default helical parameters for the helical continuum model. Stresses are given in MPa.