Study On Dynamical Characteristics Of Composite Laminate Foundation Of Shipboard

Improve the acoustic stealth performance of naval ship especially submarine, beneficial to increase combat force and survivability. When control the main noise sources (mechanical noise, propeller noise and hydrodynamic noise) about acoustic stealth, the mechanical noise made by power plant vibration occupies an important position. Power plant foundation is the base that using to fasten the power plant and transfer the power plant weight and the force arose by engine working to the ship. Using vibration isolation technology to decrease the power plant vibration and mechanical equipment vibration transmission is effective. Therefore, study on material design of the foundation structure and isolation effect becames the hot issues in engineering circles.Based on the first-order shear deformation theories and composite laminate theories, deduced the four-node finite element equations of isotropic plate and composite laminate; and deduced the two-node finite element equations of spring, the natural frequency and the mode shape of the mass-spring-foundation system are calculated by using computer code. According to the mode orthogonal principle, calculatie the first P orders mode, then combined definition of transmission function, the transfer-point mobility and driving-point mobility can be obtained. And then using velocity admittance express the power flow input and output the vibrational isolation system.On the material design of foundation structure, the effect of damping ratio coefficient is discussed. On aspect of vibrational isolation, spring stiffness is discussed.Calculate the power flow input and output system of any point.At last, take 8000 ton barge ballast pump for example, calculate the value of power flow that transmits into the supporting modeling by using isotropic plate and composite laminate.