A material-component-structure coupling damage model for the cyclic elastoplastic design of a large-span photovoltaic structure

Abstract

To reduce structural deadweight without sacrificing stiffness and strength, a large-span offshore fixed truss is designed for bearing photovoltaic devices, and correspondingly, a material-component-structure coupling methodology of cross-scale damage evolution modelling is proposed for analysing the cyclic elastoplastic behaviours of this lightweight and high-strength structure under extreme environmental loads. Utilising this methodology, the mechanical intra-action among microscale defect propagation, mesoscale component failure and macroscale offshore-truss deterioration were characterised, in which a physical relation was established through the reciprocation of the material defect propagation model and refined bulk-member elements. The cyclic elastoplastic performance of the long-span offshore fixed truss was efficiently and accurately simulated. Moreover, this damage evolution modelling provides a reasonable framework for crack prediction by considering microstructure characteristics, stress redistribution and ductile damage, because the crack of the material is caused by void nucleation, growth, and coalescence. A cross-scale modelling approach for the offshore photovoltaic structure was presented and employed to assess the key design issue that affects typhoon performance, in which a coupled solution for the micro-defects in the material and large-scale structural bearing capacity was realised. This proposed methodology can be an alternative design technique for considering the structural features and material properties in practical engineering applications.