CAJ | 학술논문

基于结构动力分析原理，以“设备基座”振动系统为例，证明结构动力分析时力边界与运动边界的统一性；针对结构局部动力参数未知情况，通过保障结构运动边界条件一致，构造结构动力分析“虚拟力”，提出结构动力分析的运动边界相似法，解决动力参数未知时给定运动边界条件的结构动力分析问题，并对其有效性进行验证；将运动边界相似法用于船舶结构水下振动声辐射研究，分析船舶水下声辐射特性。结果表明，船舶水下振动声辐射与激励作用位置、激励频率等因素密切相关。船舶结构水下辐射噪声主要集中于激励源附近的中部区域，尾部次之，船首最小；低频段船舶水下声辐射沿船长分布均匀，但随激励频率的提高，水下辐射声场不均匀性逐渐增大，指向性更明显。
기우결구동력분석원리，이“설비기좌”진동계통위례，증명결구동력분석시력변계여운동변계적통일성；침대결구국부동력삼수미지정황，통과보장결구운동변계조건일치，구조결구동력분석“허의력”，제출결구동력분석적운동변계상사법，해결동력삼수미지시급정운동변계조건적결구동력분석문제，병대기유효성진행험증；장운동변계상사법용우선박결구수하진동성복사연구，분석선박수하성복사특성。결과표명，선박수하진동성복사여격려작용위치、격려빈솔등인소밀절상관。선박결구수하복사조성주요집중우격려원부근적중부구역，미부차지，선수최소；저빈단선박수하성복사연선장분포균균，단수격려빈솔적제고，수하복사성장불균균성축점증대，지향성경명현。
Based on the principle of structural dynamics analysis,the unitarity of force boundaries and moving boundaries was proved by using the “equipment-base”vibration system as an example.By constructing“virtual force”to keep the consistency between moving boundaries of structure and locally unknown dynamic parameters,a method of moving boundary similarity (MBSM)was proposed to solve the dynamics prediction problem of a structure with given moving boundary conditions and structural locally unknown dynamic parameters.The effectiveness of MBSM was also verified.On this basis,the MBSM is applied to the research of ship structural underwater vibration and noise radiation. The underwater noise radiation characteristic of a ship was analyzed.The result show that the underwater vibration and sound radiation of the ship are highly related with the location and frequency of excitations and other factors.The ship structural borne noise radiation is mainly concentrated in the vicinity of excitation source in the middle region of ship hull. The radiation in the aft region of ship hull becomes minor and reches the minium in the region of ship bow.The underwater noise radiation is more uniformly distributed along the ship length in low frequency band;however,the inhomogeneity and directivity of the underwater noise radiation gradually increase as the excitation frequency increases.