Experimental and numerical study on creep deformation and failure characteristics of ETFE cushion structures

ETFE (ethylene-tetrafluoroethylene) cushion structures with small self-weight are typical wind-sensitive structures that are prone to large deformation and even failure under wind loads. This paper is aimed to investigate the deformation and failure behaviors of ETFE cushion structures subjected to static wind loads. Firstly, calibration mock-up experiments were carried out using a load simulation system and a photogrammetry system. Then, structural responses could be calculated based on force density theory, which were used to validate and correct the calibration numerical model inputs. Finally, same inputs from calibration numerical model were assigned to full-size numerical model and used to predict the structural behavior of a full-size mock-up in an inflation experiment. The comparison between experimental and simulation results validates numerical models integrating material creep response surface, real initial geometry, and actual loading protocol for predicting structural behavior of ETFE cushion structures. Additionally, it is observed that creep deformation constitutes a substantial portion of the total deformation under high static wind loads. The primary factors influencing the failure of ETFE cushions are identified as stress distribution and initial defects.