Study On Impact Resistance And Influence Of Marine Fuel Oil Tank

The fuel oil tank is used to store the daily fuel required by the ship’s main engine,which is an important equipment in marine power system.Then,the research on the impact resistance performance of fuel oil tank is significant to ensure the normal operation of ships and improve the vitality and combat capacity of ships.Based on the basic theory of impact dynamics,this paper establishes a numerical model of impact dynamics for a certain type of fuel oil tank.According to the relevant impact resistance specifications and standards,without considering the impact of the internal fluid on the impact resistance of the equipment,the frequency domain analysis method and time domain analysis method are used to study the impact resistance of the fuel oil tank.The calculation results show that under the impact load in the frequency domain,the vertical impact load is the most violent,followed by the lateral direction,and the smallest longitudinal direction.Under the impact of the time-domain impact load,the response of the fuel oil tank is more severe than that of the frequency-domain load impact.The time domain analysis method has put forward higher requirements on the impact resistance of the equipment.Based on the above research work,this paper further develops the research on the impact of internal fluid on the impact resistance of fuel oil tank.Using the additional mass method,the impact of the internal fluid on the impact resistance of fuel oil tank under the impact load in the frequency domain was studied.The results show that the maximum stress of the fuel oil tank when using the additional mass method is significantly higher than neglecting internal fluids.Under the vertical impact load in the frequency domain,the maximum comprehensive stress of the box increased by 71.51%.Based on the coupled Euler-Lagrangian algorithm,a numerical model of fluid-solid coupling impact dynamics is established.The effects of different liquid-fill ratios on the impact resistance of fuel oil tank is compared under time-domain impact loads.The results show that in the time-domain load shock phase,due to the short action time,the sloshing of fluid is not significant.The effect of the fluid on the equipment is mainly to increase the inertial force when the equipment is impacted.The effect of sloshing fluid has less impact on the equipment’s impact resistance.Under the vertical impact load,the maximum comprehensive stress value of the box increased by 6.37% compared with neglecting internal fluids.In addition,in the response stage after the impact load,the internal fluid generates severe sloshing under the action of inertia,and a more intense impact on the structure of the equipment,causing the stress on the impacted part to rise sharply,and the peak can reach the maximum comprehensive stress of the impact stage of 1.77 times without considering the internal fluid.It has a greater impact on the impact resistance of the equipment.The research work in this paper shows that the presence of internal fluid has a significant effect on the impact resistance of the fuel oil tank.For equipment with a certain amount of fluid inside,the influence of internal fluid should be considered in the analysis of impact resistance and its influence cannot be ignored.