Vibration Reduction And Isolation Performance Of A New Lattice Structure Formed By Laser Selective Melting

Lattice structure is widely used in spacecraft,satellites and high-speed vehicles because of its high specific strength,high specific stiffness,good energy absorption and vibration reduction performance and lightweight.SLM laser selective melting technology,as a way to slice the CAD model,lay powder layer by layer,laser irradiation,melting,cooling and condensation molding layer by layer,can shape the fine lattice structure and realize the customization of the structure.Through the damping theory and phononic crystal theory,the optimization method of damping lattice structure is deduced.Reasonably setting the parameters and array form of lattice structure can greatly improve the vibration reduction and isolation performance of lattice structure.It has considerable application prospects in the fields of aerospace vibration reduction and satellite micro vibration suppression.This thesis introduces the damping vibration suppression theory and phononic crystal theory,solves the action mechanism of lattice structure under load with the help of finite element analysis method,and explores an optimization idea of lattice vibration reduction and isolation performance.Three new lattice structure designs are proposed.The frequency response function of the four newly designed structures is calculated to verify the effectiveness of the new design.Then,the structural forming limit of slm280 of solution company is explored to find the structural parameters suitable for forming.Using Al Si10 Mgand Mn Cu alloys as raw materials,periodic array lattice structures with different lattice cells and different cell sizes with the same porosity were prepared by SLM laser selective melting technology.The performance differences of different newly designed structures and the relationship between structural performance and cell size are explored by using frequency response method,restoring static load complex force analysis method and quasi-static compression method.Finally,the simulation results are compared with the experimental results to analyze the similarities and differences of the results.The main conclusions of this paper are as follows:(1)Through the structural optimization of the basic lattice,the vibration reduction and isolation ability of the structure can be improved.The optimization method and four structures proposed in this paper are very effective.Due to the change of mass and structure,the natural frequency of the optimized structure is changed compared with the unchanged body centered cubic.(2)The lattice constant has little effect on the natural frequency of the structure,and the smaller the lattice constant is,the higher the natural frequency is.(3)For different optimized structures,the compressive stress-strain curve will show the elastic-plastic or elastic brittleness proposed in Gibson model.And the structure with arc bar has a good improvement on the stress concentration phenomenon.The conclusion shows that under the conditions of aerospace,artificial satellite in orbit and other engineering application scenarios,the structure proposed in this paper can play a good role in vibration reduction and isolation,and has greater static stiffness than BCC under the condition of low relative density,i.e.high lightweight.The results show that the structure proposed in this thesis can play a good role in vibration reduction and isolation under the conditions of engineering application scenarios such as aerospace,satellite in orbit and so on...