탄성지지 된 함정장비의 바닥기초부 조건에 따른 구조전달진동 특성에 관한 실험적 연구

Abstract

This paper is focused on the test procedure of evaluating structure-borne vibrations in supported navy equipments that cause underwater radiation noise. Since noises and vibrations, which was generated by the equipments in a special environment of naval ships, not only affect the working environment of crews living in a limited space but also reduce the fighting ability that leads to threaten the survivability of responsible persons by exposing the underwater position of hull to enemies. So the navy equipment supported by elastic mounts should be strictly controlled according to the test guideline regarding to reduce noise and vibration. Equipments mounted in naval ships in South Korea should be evaluated by the factory acceptance inspection that checks the airborne-noise and the structure-borne vibration of responsible test unit according to the US Navy standards. Because of the importance of the test procedure by US Navy standard, any environmental factors that can affect to the test results should be eliminated before conducting them to ensure the evaluation consequences on tested units. The motivation of this study is started from the effect of basement structure of the tested equipment for the measured level of the structure-borne vibration and the sensitivity of test result over the condition of basement structure was investigated for three different cases. The target supported system was selected for two cases, a vibration simulator and a fresh water generator, and the test results were compared for three different basement structure conditions, spring+fixed basement structure mass block, spring+no fixed basement structure mass block, spring only. The sensitivity of the condition of basement structure was analyzed from the measured impedance values for two different basement structure conditions and it can be figured out that the condition of basement structure plays a critical role in the evaluation result of tested target unit.