Study On The Mechanical Properties Of The Structure Of Lattice Based On Laser Additive Manufacturing

Metal lattice sandwich structure is a kind of excellent mechanical properties of structure.It has received extensive attention of scholars both at home and abroad in recent years.In this thesis,based on the related mechanical properties test of the laser additive manufacturing samples,mechanical properties of three kinds of commonly used topology forms of truss core are compared,and the frequency of the lattice sandwich structure is optimized.Firstly,finite element model of laser additive manufacturing samples,used for tensile and modal analysis,were established by finite element software ANSYS and HYPERMESH.The tensile properties of models were computed under the boundary conditions of tensile test,and the modal parameters were calculated under the boundary conditions of free vibration.The correctness of the finite element model was verified by comparing the experimental results with simulation results.The tensile and vibration properties of tetrahedral,pyramid and Kagome lattice sandwich structure under the same parameters were studied by finite element simulation.The research revealed that Kagome lattice truss core sandwich structure possessed the best tensile properties and vibration performance.Secondly,frequency of Kagome lattice truss core sandwich structure was optimized.In this optimization,diameter,angle and other parameters of core rod were set as design variables and the size and number of the unit cell is identical.Results show that the relative bulk density and angle of truss core have great influence on the natural frequency of the structure.Thirdly,the bending stiffness of tetrahedral,pyramid and Kagome lattice sandwich structure were theoretically analyzed.And equivalent mechanical performance parameters of the three structures were derived;three-point bending simulation were analyzed for previously established three modal analysis finite element models.Results show that the bending stiffness of the pyramid lattice sandwich structure is the highest,but the difference between the three was small.Finally,The mechanical properties of laser additive manufacturing products were studied.The advantages of lattice topology optimization were verified by comparing the stiffness under the same loads and constraints and natural frequency under boundary conditions of free vibration of superior frame optimized by lattice topology and that by ordinary topology.