Study On Structural Design And Designable Deformation Method Of Two-dimensional Negative Poisson’s Ratio Material

Material plays a vital role in the development of any field of a country.However,with the continuous development of modern engineering technology,traditional materials have been unable to meet the specific needs,so there is an urgent need for some emerging material technology.Among them,the negative Poisson’s ratio material is a new material attracting much attention.Negative Poisson’s ratio material is a kind of mechanical metamaterial with negative Poisson’s ratio effect,which has some excellent properties that traditional materials do not have.In this paper,the following research have been carried out for negative Poisson’s ratio material:(1)In view of the fact that most current negative Poisson’s ratio structures only have a single deformation principle,a four-angle star interlocking structure combining two deformation principles of concave quadrangle structure and interlocking structure is designed.The four-angle star interlocking unit cell is composed of deformation element and motion element.The negative Poisson’s ratio effect is verified by finite element simulation.The Poisson,s ratio and deformation of the unit cell can be controlled only by changing the deformation element without changing the whole structure of the unit cell.(2)According to the characteristic that two-dimensional perforated unit cells can adjust their Poisson’s ratio by changing their geometric parameters,a designable deformation method for two-dimensional perforated plate structures is proposed.Given target deformation requirements,the Poisson’s ratio sequence of the deformation optimization region of the structure is optimized by the optimization algorithm,and the two-dimensional perforated plate structure meeting the target deformation requirements can be obtained.The two-dimensional rectangular perforated plate structure,the two-dimensional diamond perforated plate structure and the two-dimensional elliptical perforated plate structure were optimized respectively under the requirements of six kinds of target deformation.Simulation results of two-dimensional perforated plate structures show that the proposed method can realize the designable deformation of two-dimensional perforated plate structures through optimization.(3)The feasibility and effectiveness of the designable deformation method are verified by the simulation and experimental study of the two-dimensional hybrid perforated plate structure.Nine groups of Poisson’s ratio and Young’s modulus were selected as the optimization range of Poisson’s ratio from rectangular perforated unit cell,diamond perforated unit cell and elliptical perforated unit cell.Under the requirements of four groups of target deformation,the two-dimensional hybrid perforated plate structure was optimized.Two-dimensional perforated plate samples with trapezoid,glass and hourglass shapes were prepared by 3D printing technology.The simulation analysis and experimental test results show that the two-dimensional perforated plate structure can be obtained by the designable deformation method to meet the target deformation requirements.