Optimization of spatial semi-rigid C-joint and experimental study on its rotational resistance

This paper proposes a novel semi-rigid C-joint for spatial lattice structures. In order to increase the torsional stiffness and energy-dissipating capacity of the C-joint, a joint with 'strong connection and weak plate' is proposed based on the conventional seismic principle 'strong joint and weak member'. Firstly, rational dimensions of the components were determined preliminarily through relative specifications and theoretical analysis; secondly, the nonlinear finite element model was established using the finite element software ABAQUS; thirdly, the rational dimensions of the joint components were determined through the optimization analysis carried out on the finite element model. At last, the experimental study was carried out on the proposed C-joint to investigate its mechanical characteristics. It is shown that: the proposed novel joint provides favorable ductility and torsional stiffness; the material constitutive model for the cone head of the joint affects the simulation results greatly and the tri-linear material constitutive model is proper for the simulation.