Numerical Simulation An Experimental Study On Damping Vibration Of Ships

As the main tool for maritime transportation,ships have an important position in the development of economic globalization and international trade.With the continuous advancement of ships,the problem of ship vibration has also become increasingly prominent.Harmful vibrations can cause alternating stress in the hull structure,causing fatigue damage to the hull structure and affecting the normal operation of the ship.There are two main ideas for ship vibration reduction: one is to estimate the natural frequency of the hull in the middle of the design,and change the structure or change facilities such as host propeller to stagger the frequency and achieve the vibration reduction effect.The other is to reduce the vibration of the hull by laying damping.In this paper,the experimental and simulation analysis of the structure of viscoelastic damping is carried out.The main research contents include:(1)The damping test of the inner bottom stiffened plate model,the bulkhead stiffened plate model and the double bottom model is carried out,and the random response results before and after laying the viscoelastic damping.(2)The numerical calculation method of random response of viscoelastic damping structure is studied,and the grid size and finite element type are analyzed for numerical calculation.The random response of the viscoelastic damping structure is calculated by the traditional modal strain energy method(MSE)without considering the damping frequency effect.(3)Based on the traditional modal strain energy method,the modal loss factor correction formula considering the frequency-variation effect of viscoelastic damping is derived,and the random response results of the three models are calculated.The results are compared with the MSE results and experimental results.(4)Calculate the random response results of three models when laying different thickness damping,and explore the variation law of the random response of the model.At the same time,for the double-layer floor frame,the influence of the variation of the damping laying area on its random response is further studied.On this basis,seven damping laying schemes of double-layer floor frames are designed and compared,and the laying scheme with small mass increase and good damping effect is obtained.