Italian Workshop on
Shell and Spatial Structures
Simon Guest
Department of Engineering, University of CambridgeBiography
Simon Guest is Professor of Structural Mechanics in the Structures Group of the Department of Engineering at the University of Cambridge, where he is a currently the Head of the Civil Engineering Division. His research work straddles the border between traditional structural mechanics and the study of mechanisms. His work has shown how symmetry and repetition influence the properties of both structures and mechanisms. He has worked on novel deployable structures, and has studied the mechanics and geometry of origami, initiating the development of origami-based metamaterials. A major theme of his work has been the influence of prestress on structural response, which has led to work on zero-stiffness structures, bistable structures, and tensegrity. He has worked with mathematicians interested in rigidity theory, and has recently written a book on this topic, “Frameworks, Tensegrities, and Symmetry”, published last year by Cambridge University Press.
Understanding Tensegrity with an Energy Function
The use of a simple quadratic ‘energy function’ is explored to show how it can be useful in understanding the behaviour of structures that are stressed. The energy function is quadratic in the coordinates of the structure, and is able to correctly capture the stiffness of inextensional modes of deformation that are found in, for instance, tensegrity structures. The paper shows how the quadratic energy function can be used to derive the ‘stress matrix’ that is useful both for form-finding, and for checking stability.