Research on axial stiffness of multilayer bellows under large compensation condition

In order to obtain the axial stiffness of multi-layer expansion joints, the waveform parameters of the bellows are first designed, followed by theoretical calculations of the bellows' stiffness and analysis using structural simulation software, Combining stiffness tests, the influence of contrasting mesh elements, contact conditions, and wall thickness reduction on the equivalent stress and axial stiffness of multi-layer bellows was studied using the range analysis method. The law of the axial stiffness variation in the axial elastic and plastic stages of multi-layer expansion joints was also explored. The study demonstrates that under large compensation conditions, the impact of the three analyzed factors on equivalent stress varies with an increase in the number of layers. Setting appropriate simulation parameters can enhance the computational accuracy of multi-layer bellows stiffness, thereby facilitating precise prediction of bellows stiffness.