Classification of the spatial equilibria of the clamped elastica: Symmetries and zoology of solutions

• Published in: Journal of elasticity Vol. 68; no. 1-3; pp. 95 - 121
• Main Authors: NEUKIRCH, Sébastien, HENDERSON, Michael E
• Format: Journal Article
• Language: English
• Published: Dordrecht Kluwer 01.01.2002; Springer Nature B.V
• Subjects: Boundary conditions; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Mathematical models; Physics; Solid mechanics; Static elasticity; Static elasticity (thermoelasticity...); Structural and continuum mechanics; Studies; classification of boundary value problem solutions for elastic rods
• ISSN: 0374-3535; 1573-2681
• DOI: 10.1023/A:1026064603932

We investigate the configurations of twisted elastic rods under applied end loads and clamped boundary conditions. We classify all the possible equilibrium states of inextensible, unshearable, isotropic, uniform and naturally straight and prismatic rods. We show that all solutions of the clamped boundary value problem exhibit a π-flip symmetry. The Kirchhoff equations which describe the equilibria of these rods are integrated in a formal way which enable us to describe the boundary conditions in terms of 2 closed form equations involving 4 free parameters. We show that the flip symmetry property is equivalent to a reversibility property of the solutions of the Kirchhoff differential equations. We sort these solutions according to their period in the phase plane. We show how planar untwisted configurations as well as circularly closed configurations play an important role in the classification.[PUBLICATION ABSTRACT]