@article{657.51014, title = {{Infinitesimally rigid polyhedra. II: Modified spherical frameworks.}}, author = {Walter Whiteley}, journal = {Trans. Am. Math. Soc.}, number = {1}, pages = {115-139}, volume = {306}, year = {1988}, biburl = {http://www.bibsonomy.org/bibtex/296a1fae76d1ab96cd2788b8f30f15f79/dmartins}, description = {robotica-bib}, abstract = {{From the author's abstract: ``In the first paper [ibid. 285, 431-465 (1984; Zbl 518.52010)] Alexandrov's Theorem was studied, and extended, to show that convex polyhedra form statically rigid frameworks in space, when built with plane-rigid faces. This second paper studies two modifications of these polyhedral frameworks: (i) block polyhedral frameworks, with some discs as open holes, other discs as space-rigid blocks, and the remaining faces plane-rigid; and (ii) extended polyhedral frameworks, with individually added bars (shafts) and selected edges removed. Inductive methods are developed to show the static rigidity of particular patterns of holes and blocks and of extensions, in general realizations of the polyhedron. The methods are based on proof techniques for Steinitz's Theorem, and a related coordinatization of the proper realizations of a 3-connected spherical polyhedron.'' \par For example, the author proves the following type-(i) theorem: an abstract block and hole polyhedron, with a single k-gonal hole and a single k-gonal block, is generically isostatic if and only if the hole and block are k-connected (in a vertex sense). He gives complete definitions, rigorous proofs, and mentiones some related results and open problems.} }, reviewer = {{J.Mueller}}, language = {English}, classmath = {{*51M20 Regular figures in space 52Bxx Polytopes and polyhedra 70C20 Statics}}, keywords = {4-connected Steinitz's Theorem} frameworks; generic graph; polyhedral rigidity; static {infinitesimal } }