Mechanical Properties Of QuadDiametral Type Lattice And Its Topological Homogeneous Mode Application

The lattice structure possesses remarkable characteristics,including lightweight,high strength,and a high energy absorption ratio,and design flexibility,which makes it widely used in fields such as biomedicine,spacecraft,airplanes,and automobiles.However,as its application deepens,it has become difficult for simple lattice structures to adapt to situations such as multiple impacts and areas with different density variations.Therefore,it is particularly important to establish a mathematical model of the lattice structure and design more complex lattice structures.This paper focuses on the Quad Diametral lattice structure and aims to investigate its mechanical properties and failure mechanism under both quasi-static and impact loading conditions.The findings of this study are of great importance for the practical application of lattice structures.The main research objectives of this study are as follows:(1)To address the problem that the factors influencing the elastic modulus of Quad Diametral lattice are still unclear,we adopt the beam unit as the reference and analyze it with the classical static theory,and then obtain the mathematical model of its elastic modulus.Based on the LCD printing technology,the theoretical model is verified by a combination of experiments and numerical simulations.The results show that the elastic modulus of the lattice is positively correlated with the magnitude of E and ?,and negatively correlated with the magnitude of l/ d.The error between the simulation and experimental results and the theory is within 8%,which verifies the accuracy of the derived theory.(2)With equal average porosity as the constraint,seven gradient point structures with different porosity variation strategies were designed and prepared by controlling the field volume function.A combination of experiments and numerical simulations was used to firstly explore the damage modes of the lattice structures under quasi-static compression and impact modes.Then the mechanical properties such as elastic modulus,yield strength,unit absorption energy and first peak stress are quantitatively analyzed in relation to the gradient change strategy.The results show that the smaller the gradient span and the closer the deformation mechanism is to uniform lattice in linear gradient lattice,the better its mechanical properties are;in exponential gradient lattice x3 has the best mechanical properties due to its smooth transition curve,its compression modulus and yield strength are about 20-50 lattice The compressive modulus and yield strength are about 1.3 times of those of 20-50 lattice,and the unit absorption energy and the first peak stress are 1.3 and 1.5 times of those of 20-50 lattice,respectively.(3)The 3D model of the hip joint was reconstructed based on the CT data of volunteers,and based on this,a replacement hip joint was designed to replace the necrotic part of the femoral head.The stresses on the hip joint were simulated under various working conditions such as standing,walking and stairs,and the topology of the acetabular cup and stem were optimized according to the stress distribution.The results showed that x3 fractional implantation resulted in a 25% weight reduction and an 18.5% decrease in the stress shielding rate.This paper focuses on the mechanical properties of Quad Diametral-type punctures based on a combination of experimental and numerical simulations,and quantitatively analyzes the effects of rod-diameter ratio,angle and gradient change curves on the damage mode,loadbearing capacity and energy absorption of the punctures structure,and applies them to hip replacement.This paper can provide a certain theoretical basis for the design of multi-angle punctures.