## 4 Results and Discussion
### Simulation Results
#### 4.1.3 Results under Extreme Temperature Conditions  
Figure 10 shows the von Mises stress of the O-ring in the inflation state under two distinct working conditions. Compared with the deflation state at 15 \({}^{\circ}\)C and 70 MPa, the high-stress area in the deflation state at 130 \({}^{\circ}\)C and 87.5 MPa no longer maintains a symmetrical distribution in the middle of the O-ring; it shifts downward towards the left and right lower corners of the O-ring. Significantly, the maximum von Mises stress of the O-ring decreases by 65% under this specific working condition. The results show that in the inflation state at 130 \({}^{\circ}\)C and 87.5 MPa, the stress concentration of the O-ring is reduced and it is less susceptible to damage. Figure 11 shows the contact pressure of the O-ring in the inflation state under two different working conditions. Both contact surface I and contact surface II under the two working conditions can realize the sealing function. Compared with the inflatable condition at 15 \({}^{\circ}\)C and 70 MPa, the maximum contact pressure of contact surfaces I and II at 130 \({}^{\circ}\)C and 87.5 MPa is reduced by 40%, and the effective sealing lengths of contact surfaces I and II are both reduced by approximately 20%. The results show that the sealing performance of the O-ring is influenced by the working conditions, and the sealing effect is weakened in the inflation state at 130 \({}^{\circ}\)C and 87.5 MPa. Figure 11: Contact pressure of the O–ring in the inflation state under two working conditions: (**a**) 15 \({}^{\circ}\)C and 70 MPa; (**b**) 130 \({}^{\circ}\)C and 87.5 MPa. Figure 10: von Mises stress of the O–ring in the inflation state under two working conditions: (**a**) 15 \({}^{\circ}\)C and 70 MPa; (**b**) 130 \({}^{\circ}\)C and 87.5 MPa. Figure 12 shows the von Mises stress of the O-ring in the deflation state under two different working conditions. Compared with the deflation state at 15 \({}^{\circ}\)C and 70 MPa, the von Mises stress of the O-ring at \(-\)60 \({}^{\circ}\)C and 56 MPa is symmetrically distributed in the middle. In addition, the stress concentration is serious, and the maximum von Mises stress increases by 7 times. The results show that the stress concentration of the O-ring in the deflation state at \(-\)60 \({}^{\circ}\)C and 56 MPa is much more serious than that in the deflation state at 15 \({}^{\circ}\)C and 70 MPa. Figure 13 shows the contact pressure of the O-ring in the deflation state under two different working conditions. Both contact surface I and contact surface II under the two working conditions can realize the sealing function. Compared with the deflation state at 15 \({}^{\circ}\)C and 70 MPa, the maximum contact pressure on contact surfaces I and II in the deflation state at \(-\)60 \({}^{\circ}\)C and 56 MPa increases by a remarkable 7 times, with the effective sealing length of contact surface I doubling. The contact pressure and sealing length of the contact surface directly determine the sealing performance of the seal. The results show the outstanding sealing performance of the rubber O-ring in the deflation state at \(-\)60 \({}^{\circ}\)C and 56 MPa. To improve the clarity and completeness of presentation, as well as to provide a more informative and accurate depiction of the contact stress distribution at \(-\)60 \({}^{\circ}\)C, we have added Figure 14 to this paper. Figure 14a depicts the contact area of contact surface I and contact surface II of the sealing ring. Figure 14b illustrates the inner diameters of the effective sealing areas for contact surface I and contact surface II, which are 7 mm and  
Figure 12: von Mises stress of the O–ring in the deflation state under two working conditions: (a) \(-\)60 \({}^{\circ}\)C and 56 MPa; (b) 15 \({}^{\circ}\)C and 70 MPa. Figure 13: Contact pressure of the O–ring in the deflation state under two working conditions: (a) \(-\)60 \({}^{\circ}\)C and 56 MPa; (b) 15 \({}^{\circ}\)C and 70 MPa. 8.2 mm, respectively.