Investigation of the Failure Mechanism and PTFE Strength Reduction of Double-Layer Orthogonal Cable-Membrane Connections

This study aimed to evaluate the mechanical properties and PTFE (Polytetrafluoroethylene) coated membrane strength reduction coefficients of the original cable-membrane connection of a double-layer orthogonal cable-membrane structure. First, two kinds of membrane connections applicable to the double-layer orthogonal cable-membrane structure were introduced. Subsequently, considering the influence of the membrane configuration, 36 loading specimens were designed to carry out tensile experiments on the cable-membrane connection. By examining the experimental results, the failure mechanism of the connections was revealed. The connection failure loads at different membrane angles and configurations were tested, and the corresponding load—displacement curves were obtained. Furthermore, the factors affecting the connection mechanical properties were analysed, and the relationship between membrane stress and strain was deduced. Finally, the membrane strength reduction coefficient corresponding to the proposed connections was calculated, and the suggested value was given to provide a basis for designers applying the connection. The results show that the mechanical properties of the connection are affected by a variety of factors, including the membrane angle, membrane configuration, connection method, and material properties. The reduction factors of the different connections are as follows: the clamping connection factor is 0.35, the biting connection membrane with long ridges and short ridges is 0.25, and the biting connection without reinforcement membranes is 0.2.