Analysis Of Mechanical Properties Of Composite Gradient Lattice Strcuture

Lattice materials as a lightweight porous materials, which appear in recent years. Because of its lattice configuration, it has fine mechanical properties such as lightweight, high porosity, high strength, high stiffness, high toughness, high energy absorption and so on. At the same time, the gap can meet the other functional requirements, such as sound absorption, shock absorption, heat dissipation, electromagnetic shielding, and so on. Therefore the study of mechanical properties of the lattice structure is of great guiding significance.The main research object of this paper is the Pyramid type composite gradient lattice structure. The structure is composed of two thin panels with high rigidity and a kind of truss structure in the middle of the upper and lower layers. The lightweight core material can effectively increase the ability to withstand the shear load. The study on the equivalent stiffness can not only help us to understand the mechanical properties of the structure better, but also pave the way for the research in the special environment.This article is based on the theory research of the pyramidal lattice composite sandwich structure mechanics performance. The analysis of the lattice structure of a single cell model is carried on through the homogenization method. The core rods are regarded as beam structure, under the assumption of small deformation and non-prestress. Through energy method, we can establish the equation of stress-strain relationship using tensor. And the equivalent stiffness matrix of lattice structure can be derived. Then the influence of geometric parameters on the whole equivalent stiffness is studied.Then the structure equivalent finite element model is set up. When the original structure and the equivalent structure are under the same uniform load. We can know whether the equivalent stiffness is accurate through the comparative analysis of the displacement field distribution of them. At the same time, the vibration characteristics of the original model and the equivalent model under different constraints are analyzed.Finally, the lattice structure model of different gradient distribution is established by using the method of PCL language parametric modeling. The vibration characteristics and carrying capacity of the gradient structure of the intermediate and the two ends are studied respectively, and compared with the uniform lattice structure of the same quality and the same size.Increasing the density of the lattice cell in the structure of the main stress part, and reducing the cell density in the stress smaller part can effectively reduce the structure of the stress value to enhance the carrying capacity. At the same time, the design of the gradient can also meet the requirements of the structural load, to reduce the structural quality further.