Bending characteristics of the reinforced S-shaped bellows under internal pressure

The reinforced S-shaped bellows, which can withstand high internal pressure, is a kind of typical metal bellows in aerospace and nuclear industries. Bending deformation is a typical displacement compensation of the reinforced S-shaped bellows. The discussion on bending characteristics of bellows under internal pressure has strong background of engineering application. In the present study, theoretical and numerical simulation analysis methods were introduced to investigate the bending characteristics of reinforced S-shaped bellows under internal pressure. Three different mechanical behavior characteristics were found in the whole bending process, they are high-rigidity, low-rigidity and rigidity sharply increase states. The state transition is mainly related to material nonlinearity and fitting relationship between bellows and reinforced hoop. Bending moment increases with the increase of internal pressure at the same angel of rotation, while both yield and sharply increase points forward. Although internal pressure makes the bellows yield earlier, the overall structure can still maintain a high displacement compensation capacity. •Numerical simulation analysis of bending characteristics was performed for reinforced S-shaped bellows.•Three different mechanical behavior characteristics were found out in the whole bending process.•The overall structure can still maintain a high displacement compensation capacity under internal pressure.