Dynamic analysis and structural design of links in an air circuit breaker to enhance fatigue life

Abstract

A systematic method as applied to an air circuit breaker (ACB) system is proposed to analyse the links of the spring-actuated linkage under repetitive impact loading. A fatigue life equation applicable to the links is presented on the basis of the fatigue test. The result obtained from the multi-body dynamic analysis is compared with that from the experiment. For the explicit finite element analysis of the links, the impact loading obtained from the dynamic analysis of the ACB system is used as the initial conditions. To enhance the fatigue life of a weak link, two modified designs are proposed and their maximum stresses are reduced very much compared with that of the original design. Considering a safety margin, one modified design satisfies the required specification of the fatigue life. The proposed approach in this work can be efficiently used in designing stable and reliable links of the ACB and in analysing a similar spring-actuated linkage system.