Contributions of wind-induced overall and local behaviors for internal forces in cladding support components of large-span roof structure

摘要

Internal forces in cladding support components of large-span roof structures under wind loads were usually estimated only based on the local wind loads imposed on tributary areas. However, internal forces on such members depend not only on local behaviors caused by local wind loads but also on wind-induced overall behaviors of main structural frames. By ignoring the contribution of overall behaviors of main structural frames, internal forces in cladding support components may be underestimated following current wind load codes or recommendations. It is necessary to investigate the contributions of local and overall behaviors to improve the wind-resistant design of the cladding support component members on large-span roof systems. In this paper, a method was proposed to separate the internal forces of cladding support components due to wind-induced local and overall behaviors and investigate the corresponding contributions for the largest internal forces. Wind loads used for loading effects estimation were obtained based on wind pressures measured from a 1:400 scaled roof model under a boundary layer wind flow configuration. Wind loading effects considering wind-induced total behaviors (overall behaviors and local behaviors together) for axial force, bending moment and shear force were calculated by time-history analysis using finite element (FE) models of the prototype structure. Meanwhile, internal forces in cladding support components only considering local behaviors were extracted by using local wind loads based on quasi-static assumption. Finally, based on the contributions to the largest wind-induced internal forces resulting from the proposed method, a procedure for remedying the current wind load codes for such members were discussed.