arXiv subjects
Publications and source records attributed to Gerald D. Nelson.
We demonstrate the existence of four types of flexible prismatic polyhedra that can be derived or inferred from a consideration of Bricard octahedra and generalizations of Bricard octahedra. These flexible polyhedra are of genus 0 and 1, have dihedral angles all of which are non-constant under flexion, have faces that exhibit self-intersections, have an indefinite number of faces and have vertex motion that can treated as a function of a single variable.
We study the flexibility of suspensions (polyhedra having the combinatorial structure of dipyramids) that have an even number of vertexes and provide arguments that there are least five distinct types of flexible suspensions.
We construct five types of polyhedra by generalizing the description of Bricard octahedra and applying the generalizations to polyhedral suspensions. The resulting polyhedra are flexible, are of genus 0, exhibit self-intersections, have zero oriented volume, have dihedral angles all of which are non-constant during flexion and are of indefinite size, the smallest of which are dodecahedra with eight vertexes.
We demonstrate the construction of several families of flexible polyhedra by extending Bricard octahedra to form larger composite flexible polyhedra. These flexible polyhedra are of genus 0 and 1, have dihedral angles that are non-constant under flexion, exhibit self-intersections and are of indefinite size, the smallest of which is a decahedron with seven vertexes.