Research On 3D Lattice Gradient Filling Method Based On Energy Distribution

Because lattice structure has a series of characteristics such as specific strength,specific stiffness,energy absorption and heat dissipation,it has been widely applied in aerospace,vehicle,medical,ship and other fields.With the development of additive manufacturing technology,lattice structures have been widely studied and applied,breaking the constraints of manufacturing difficulties.At present,the realization of the integration of lattice material-structure-function and the structural and geometric characteristics of multi-materials,multi-scale and multi-layer are the current goals.In this thesis,the multifunctional gradient lattice material filling design of the motor shell was carried out using the four-pyramid lattice structure in the truss lattice structure.The main research contents are:Firstly,the pyramid lattice structure was selected from the truss lattice structure as the research object;Based on the basic operating principle of EHA,the motor shell was preliminarily analyzed and a fixed-point array filling scheme was proposed.Then,the relative density of the pyramid lattice structure were modified considering the overlap effect at the nodes;The calculation methods for the equivalent elastic modulus and yield strength of the pyramid lattice structure and BCC lattice structure based on the Euler-Bernoulli beam theory and the Timoshenko beam theory were introduced respectively,and compared with the simulation results to prove the advantages of the Timoshenko beam theory in calculating small aspect ratio lattice structures;In the case of large deformation,the relationship between strain energy and relative density was deduced based on the principle of rotation failure of BCC lattice structure around plastic hinge structure,and the validity of the mathematical model was proved by comparison with the finite element analysis results,subsequently,the finite element analysis results were used to fit the calculation methods of strain energy and relative density of the pyramid lattice structure.Finally,an energy gradient lattice structure was designed based on the strain energy distribution of the structure,and compared with linear gradient lattice structures and uniform lattice structures,it was found that this structure has certain advantages in energy absorption.Finally,based on the SCDM software platform,the automatic modeling of non-uniform lattice structure is realized through secondary development and gridding technology;The motor shell is filled with functional gradient lattice,and the structure is checked by finite element simulation software,and the results meet the design requirements.