Numerical analysis of wrapped boot torque characteristics of miniature flexible joint

To investigate the wrapped boot torque characteristic of miniature flexible joint, a miniature flexible joint with silicone rubber elastomer and wrapped boot was designed. The 3D finite element models of flexible joint with boot and without boot were set up respectively. The second order invariant model was used to describe the constitutive relationship of the silicone rubber. The stress of the flexible joint with boot and without boot under different pressure with the same deflection angle was computed. The boot torque was obtained by subtracting the torque of flexible joint without boot from the total system torque. In addition, the shear stress on the boot under different pressure was analyzed. In order to verify the validity of the model, the simulation and experimental results of the boot torque under different pressure were compared. Results show that the simulation boot torque has a good agreement with the experiment data. Boot torque decreases with enhancing pressure and it is caused by the shear stress of the boot section.