Shock response analysis for reed contact switches in naval ships' electrical equipment

Reed contact switches are widely used in the naval ships' electrical equipment. When subjected to explosion impact, a reed contact switch tends to turn-off or the reeds produce plastic deformation to affect the reliability of equipment and endanger the safety of ships. To check the shock resistance ability of a reed contact switch, the contact modes of the closed switch were analyzed firstly, and then its responses under several typical impact loads were calculated with Bathe composite integration method. Finally, whether the reed contact switch became open circuit was determined by extracting the contact force between the dynamic contactor and the static contactor, while whether the reeds plastically deformed under impact loading was observed. It was shown that the contact force between contactors fluctuates under impact loading while there is a clear periodicity in its free vibration with the vibration frequency close to its first-order natural frequency; in the case of the same amplitude, higher frequency impact loads are more likely to cause violent contact chatter and broken circuit, while lower frequency impact loads cause the larger stress and plastic deformation at the root of reeds. The influence of negative wave delay on the shock response was discussed, and measures to improve the reed contact switch's shock resistance ability were proposed. © 2016, Chinese Vibration Engineering Society. All right reserved.