Abstract

Four sets of necessary and sufficient conditions are obtained for the first-order rigidity of a periodic bond-node framework C in Rd which is of crystallographic type. In particular, an extremal rank characterisation is obtained which incorporates a multi-variable matrix-valued transfer function ΨC(z) defined on the product space C⁎d=(C﹨{0})d. In general the first-order flex space is the closed linear span of polynomially weighted geometric velocity fields whose geometric multi-factors in C⁎d lie in a finite set. It is also shown that, paradoxically, a first-order rigid crystal framework may possess a nontrivial continuous motion. Examples of this phenomenon are given which are associated with aperiodic displacive phase transitions between periodic states.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.