Form Finding and Optimisation of Bamboo Gridshell Structures

Abstract

This paper presents the utilisation of parametric tools for bamboo gridshell structure design through form finding and optimisation to obtain structure-efficient forms. Models of gridshell structures were developed in Rhinoceros using plug-ins Grasshopper and Kangaroo, by defining the designated span, height, grid configuration, and mesh size. The structural behaviour of the models was analysed through Finite Element Analysis (FEA) using Karamba3D to obtain the stress distribution and deformation. The input mechanical properties were obtained from material tests of three Indonesian bamboo species: Gigantochloa apus, Gigantochloa atter, and Dendrocalamus asper. Based on the FEA result, the structural efficiency was considered for optimisation, and the iterative process of structural optimisation was done by modifying these parameters: strength usage, number and size of the members to obtain optimised gridshell forms. The form finding and optimisation process demonstrated generating efficient gridshell structures using bamboo and is envisaged to be applicable for further bamboo gridshell design.