Parametric Design And Mechanical Properties Of Porous Structures Based On Triply Periodic Minimal Surfaces

In the field of modern manufacturing,rapid design and analysis of structures has always been a research hotspot.Combined with additive manufacturing technology,parametric design can achieve matching with structural functions.However,how to regulate the mechanical properties of the structures through parametric design is a very challenging research topic.Triply Periodic Minimal Surfaces are a smooth and fully connected periodic porous structures with excellent geometric and mechanical properties,which are widely used in medical services,architectural design,material chemistry and other fields.This paper mainly studies the parametric design and analysis based on the triply period minimal surfaces.Using the Grasshopper parametric modeling platform,starting from multiple parameters,the mechanical performance of different TPMS is explored,and the performance mechanism of porous structure under different parameters is revealed,and applies it to the example design of porous structures.The main research contents and methods are as follows:(1)Parametric modeling based on spatial lattice.Based on the implicit surface function and spatial lattice,the modeling of different triply period minimal surfaces is realized.A design method of determining structural parameters from geometric parameters is proposed.The structural design of minimal surfaces is carried out through parameters such as thickness,period and rotation angle.The functional relationship between geometric parameters and structural porosity is established,and a strategy to adjust the variable periodic structures with arbitrary porosity by changing the thickness is studied.(2)The relationship between design parameters and mechanical properties.Taking porosity as the research object,the periodic laws of periodic parameters and structural stiffness are revealed by using the control variable method.Through quasi-static compression test,the mathematical relationship between porosity and Young’s modulus is established,and a design method of porous structures with functional gradient is proposed.The results show that the designed gradient bone has a reasonable pore size distribution,the Young’s modulus meets the stiffness requirements and has good mechanical continuity.(3)The application of the proposed design method in the design of porous structure of shoe midsole.Taking the design of shoe midsole as an example,through plantar pressure analysis and data acquisition,driving structure generation through design parameters.By changing the parameters of period and rotation angle,the design space is divided into cells,the gradient porous structures with globally controllable and local uniform pores are designed.In order to verify the proposed design and method,the solid printing and experiment of the designed gradient shoe midsole structures are carried out.The results show that the designed gradient shoe midsole structures can well reduce the peak force of the sole,alleviate the burden of the foot,and play a good cushioning role.