Experimental study of leg member bolted joint slippage and its effects on mechanical behavior of lattice transmission tower

Lattice transmission towers are typical spatial truss structure, which are commonly composed of equilateral angle steel members using bolts. Different from the bolted joints in beam-column connections of steel frame structures, bolted joints in lattice transmission tower are normally under great axial force and negligible bending moment. Joint slippage will affect the performance of the members under large axial force and even change the behavior of the lattice tower structure system. Therefore, it is very important to establish the joint slippage model for the analysis of lattice transmission towers. Firstly, this study investigates the process of joint slip through a series of tensile tests and analyses the influence of different structural parameters on the slip characteristics of bolted joints. Then, an exponential joint slippage model for the bolted joint of leg member used in steel lattice transmission power is established based on the experimental results. Finally, the finite element model of the transmission tower considering joint slip is established. The influence of different slip models on displacement and axial force of the transmission tower is analyzed.