Simulation and analysis of mechanical properties of cold-formed lock-seam of truss rods for on-orbit construction

Abstract

In this paper, a new process of spiral cold forming of truss rods for on-orbit construction is proposed. The influence of the width of the lock-seam overlapping region, stirp thickness and lock-seam buckle structure types on the mechanical properties of the rods’ lock-seam was investigated by using a method combining of single tensile experiment and numerical simulation. The results show that for the flat buckle samples with the stirp thickness of 0.3 mm, with the increase of the width of overlapping region of the lock-seam, the maximum occlusal force and maximum occlusal strength of the lock-seam are monotonically decreasing. Although the simulated maximum occlusal force is slightly higher than the actual maximum occlusal force, the simulation results show reasonable agreement with the experimental values. In the simulation, with the increase of the stirp thickness, the maximum occlusal force of the flat buckle has a linear increase, while the maximum occlusal strength increases slightly. Compared with the flat buckle type, when the lock-seam is designed as a pressed rib buckle type, the overall mechanical properties of the lock-seam are improved by 80%. It is more effective to improve the mechanical properties of the rods’ lock-seam by changing the buckle type.