Research On Tank Body Lightweight Of Liquid Tank Truck Based On Bidirectional Fluid-structure Coupling

The volume of liquid transportation is rapidly increasing as China’s economy develops.Because of its ease and great transportation efficiency,the liquid tank truck has become the primary liquid transportation instrument.Liquid has different physical properties from solid goods.Whenever the car holding the liquid tank brakes or turns,the liquid in the tank will impact the tank,causing damage to the structure.In serious cases,it will also cause the tank car to slide and roll over,which is a great potential safety hazard.At the same time,the implementation of national emission reduction measures and the promulgation of overload regulations have made overloading become an urgent problem to be solved,and Lightweight has become an inevitable trend in the development of the automotive industry.Hence,it is very important to conduct research to meet the loading requirements and ensure the safety of the transportation of liquid tank vehicles.Based on gas-liquid two-phase fluid-structure coupling theory,mechanical modeling and bidirectional fluid-structure coupling analysis method are adopted to build bidirectional fluidstructure coupling analysis models of liquid tanks with different filling ratios.The influence of liquid sloshing on tank structure stress under extreme braking and steering conditions was studied systematically,and the optimization design of tank thickness was achieved by using a multi-objective genetic algorithm to achieve the purpose of lightweight.The main research contents are as follows:Firstly,with the specific structural dimensions of a liquid tanker,Solid Works 3D modelling tool was used to complete the structural modelling of the tank,and Ansys Workbench software was used to built a two-way simulation model environment for fluid-solid coupling,including finite component analysis of the solid-liquid structural model,the multi-phase flow model and dynamic mesh building,so as to prepare for the subsequent co-simulation.Second,through to the tank truck to simplify the structure model,design of tank truck limit load condition under braking,steering,construction of a finite element simulation analysis model based on different liquid ratios and different filling media.two-way fluid-structure coupling method by simulating the interaction force of liquid and tank,by comparison with the simulation results,The liquid sloshing mechanism and stress variation and distribution law with time history under different filling ratio and different filling medium were obtained,which provide a theoretical baseline and data support for subsequent optimization and improvement.The third strength theory is used to evaluate the stress intensity of tank.Finally,to improve the calculative efficiency,a 1:10 scale model of a liquid tanker was built.In order to ensure the boundary transition between cylinders of different thickness and the follow-up update of fluid domain size in the optimization process,the constraint conditions based on function equation were designed and the Pareto optimal solution graph was constructed based on multi-objective genetic algorithm optimization calculation.The comparison and analysis of the performance indices before and after optimization were carried out.The results show.The overall mass of the optimized model was reduced by 8.6%.The stress intensity analysis of the optimized model shows that the strength requirements are met.