Dynamic properties of a bamboo-steel spatial truss structure

The main characteristics of an original bamboo-steel composite structure are presented. This novel structural system has been conceived to realize large roofs and bridges, in such a way to ensure easy and rapid construction, efficient use of the constituent materials, low manufacturing costs and high environmental sustainability throughout its lifetime. Specifically, the considered structural system is a spatial truss whose upper chord and diagonal bars are made by GluBam elements whereas its lower chord is made of steel tubes. The prototype spatial truss beam built and tested in the laboratories of Nanjing Tech University is initially presented. So doing, some details about geometry and joints of the truss structure are given. Finally, the results obtained from preliminary dynamic experimental tests are also discussed. In particular, the dynamic response under ambient vibrations and the free-decay response of this truss structure have been recorded and analysed in order to estimate its modal properties. Overall, the obtained results indicate that the damping values of bamboo trusses with steel joints and members are comparable with those usually recommended for timber structural systems and are suitable for uses in common practice.