Effective strain range-based prediction and analysis of the fatigue life of pipette shaft seal ring

The accuracy of nucleic acid extraction and diagnosis depends on the sealing performance of the pipetting device. The rubber seal ring at the front end of the pipette shaft is a critical component for ensuring the sealing performance of the pipetting device. In this study, an accurate prediction and analysis were made on the fatigue life of the pipette shaft seal ring. ABAQUS was used to simulate the assembly process of pipette shaft seal ring and disposable tip, and the dangerous cross-section segments on the seal rings were preliminarily identified according to a stress nephogram. Based on the continuum damage mechanics theory, the fatigue life prediction model was built where the effective strain was taken as a damage parameter, and the fatigue life of the dangerous cross-section of the pipette shaft seal ring was calculated. By observing failed seal rings in actual use, it was found that the worn positions of the failed seal rings were the same as the sites of the shortest-lived node segments, thus verifying the accuracy of fatigue life prediction model and fatigue life analysis.