Papers by Author: Hee Jin Shim

Abstract: The study aimed at the fatigue life estimation for leakage of refrigerant used in household air conditioner. The leakage of brazed joints was affected by the manufacturing faults with flaws and service condition which is at the internal pressure and at the excitation. Therefore, the four point bending tests were performed to estimate effects of internal pressure and excitation for the fatigue life of brazed joints. In addition, to investigate effect of internal pressure and excitation on the fatigue life, the orthogonal array table in Design of Experiment is adopted.

Abstract: The study aimed at the failure analysis and strength evaluation of brazed joints used in household air conditioner. For these goals, the failure modes were investigated through the fractographic analysis and micro-Vickers hardness test. The failure modes were classified into two different types and their mechanism was influenced by heat and internal flaws such as incomplete penetration and pin holes. Also, a finite element analysis was performed to evaluate the strength behavior of the brazed joints according to the heat and internal flaws.