Static behaviour and simplified design method of a Tensairity truss with a spindle-shaped airbeam

摘要

To provide solutions for large span structures, the use of a Tensairity truss with a 60-m span, which was studied numerically, is proposed. The influence of the internal pressure and cable tension length on the mechanical properties is investigated for several load cases. A simplified spring model based on the vertical stiffness formula of the inflated airbeam is presented, and a static design principle and a design method are proposed. The results show that the adoption of a steel truss can greatly increase the spanning capacity of a Tensairity structure, and the stiffness and load bearing capacity for the structure increase with the increase in air pressure. However, the structure is very sensitive to wind load, which can be improved by re-tensioning the lower cable. Comparisons between the simplified spring model and the original model show a good correlation for the displacement distribution and overall stiffness at a relatively high internal pressure for all load cases considered. The simplified design method will be an easy way for designers to evaluate the behaviour of Tensairity structures, and can be conveniently applied to practical engineering cases. (C) 2018 Elsevier Ltd. All rights reserved.