Structural Optimization For Train Water Tank Based On Fluid-structure Interaction

The train water tank belongs to the mobile water storage container.Compared with the fixed container,the train water tank will not only be subjected to the pressure of the internal liquid due to gravity,but also in the course of the train operation.Due to the continuous improvement of the speed of train in China,the problems of anti-wave plate shedding and leakage caused by liquid sloshing on the water tank are becoming more and more prominent.In addition,it will be subjected to vibration load.Therefore,the train water tank has special requirements in structure.According to the specific requirements of the company and the relevant national standards,this paper took the 1500 L train water tank as the research object:(1)Based on the 2D drawings provided by the company,the model of the water tank box and the internal fluid was constructed by using software.Water tanks and fluids were meshed using software.The finite element model of water tank was modeled by shell element and solid element,and quadrilateral mesh was used for shell element and hexahedron mesh was used for solid element.The fluid finite element model adopted triangular surface mesh and tetrahedral mesh.And finally it obtain better mesh quality and meet the requirements of mesh accuracy.(2)When the filling coefficient of water tank was 1.0,the pressure distribution cloud diagram was obtained by using software.Based on the fluid-solid coupling method,the strength and deformation of the box were simulated and analyzed.It shows that the analysis results of water tank accord with the national standard.(3)According to the relevant national standards,the impact simulation of the water tank with different filling coefficients in the longitudinal direction was carried out in software.Based on the fluid-solid coupling method,the impact conditions of water tanks with different liquid filling coefficients were simulated.According to the gas-liquid two-phase distribution diagram,the existence of wave-proof plate can effectively alleviate the impact of liquid and reduce the impact load of liquid on the inner wall of water tank.The results show that the maximum stress under the impact condition is less than the yield strength of the material,and the maximum stress position is at the welding place of the anti-wave plate and the water tank.The impact stress on the inner wall and the anti-wave plate increases with the increase of the liquid filling coefficient.(4)Based on the MOGA algorithm,the response surface analysis module of Workbench was used to optimize the structure design of the water tank.The design variable was the aperture of the anti-wave plate and the parts of the water tank.Maximum stress is a constraint condition,and maximum deformation and minimum mass are the objective parameters.The optimization scheme of train water tank structure proposed in this paper.It provides the basis for the manufacturer to improve the design.(5)The simulation tests of dry mode and wet mode of the optimized tank are carried out,and the natural frequency and the first six mode images of the tank with different liquid filling coefficients are obtained.The experimental results show that when the water tank is resonant,the deformation of the water tank is large,and the relationship between the filling coefficient and the natural frequency of the water tank is obtained.