Microstructure Design And Mechanical Properties Control Of Bio-inspired Materials

Control and design of microstructure structures are important means to break through the limits of material mechanics and obtain high-performance structural materials.Biological materials,with their special three-dimensional microstructure and damage energy dissipation mechanisms,can achieve superior mechanical properties beyond their components,providing rich and effective structural design references for the regulation of material microstructures.By analyzing the structure-property relationship in biological materials,extracting the toughening and energy dissipation mechanisms of biological materials,and combining advanced materials preparation methods,it is possible to design high-performance biomimetic structural materials that surpass existing engineering materials.Despite a series of advances,the performance improvement of biomimetic structural materials compared to their components still falls far short of the superior level of biological structural materials.In-depth research on toughening and energy dissipation mechanisms in biomimetic structures,and specific analysis of the influence of microstructure parameters will help further improve the performance of biomimetic structural materials and provide a universal biomimetic structural design scheme for the preparation of high-performance structural materials.Therefore,this article develops a mechanical analysis method to characterize the structure-property relationship of biomimetic materials,studies the correlation between damage energy dissipation mechanisms and loading conditions and structural parameters of biomimetic structures,and proposes a mechanical optimization design scheme for microstructure cutting of biomimetic structural materials.The research results are summarized as follows:Firstly,the relationship between the damage energy dissipation mechanism of the nacre-like structure and the impact velocity was studied.We fabricated a nacre-like glass structure through a combination of laser engraving and laminated assembly,as well as a nacre-like composite material structure which was synthesized using threedimensional printing technology in conjunction with a corresponding digital model.Through experimental research on mechanical testing and damage characterization,combined with micro-mechanical finite element numerical simulation,the mechanical properties and damage mechanism of the nacre-like structure under different impact velocities were investigated in detail.It was found that the nacre-like structure only exhibits superior impact resistance in a certain range of low impact velocities,when the brick sliding mechanism in the structure can be fully activated.When the impact velocity exceeds a certain critical value,the non-elastic deformation energy dissipation of the nacre-like structure saturates,and the laminated structure is more suitable as an anti-impact template than the nacre-like structure.Finally,a mixed structure design strategy that optimizes the placement of different structures during the impact velocity attenuation process is proposed to achieve optimal impact resistance performance over a larger range of impact velocities.Secondly,the correlation mechanism between the mechanical properties and microstructure parameters of biomimetic materials under different impact velocities was analyzed.Taking the nacre-like structure,laminated structure,and monolithic structure as examples,the influence of various structural size parameters and impact boundary conditions on the impact resistance performance of structural materials at different hammer velocities was studied.It was found that structural size parameters and impact boundary conditions affect the numerical value of the energy dissipated by the structure,but under different parameter conditions,the impact resistance performance of the nacre-like structure is always surpassed by the laminated structure at higher impact velocities.The different damage failure mechanisms of the nacre-like structure and the laminated structure exhibit different velocity-related properties,leading to the phenomenon of reversed impact resistance performance advantages.This indirectly explains why shells with nano"brick-mud" structures in nature can be shattered by predators at a certain velocity.At the same time,the optimization direction of structural parameters to regulate the impact resistance performance of the nacre-like structure is given.Thirdly,a bio-inspired composite glass material was designed by combining the advantages of nacre-inspired structures and shear-thickening materials.The bio-inspired composite glass material combines the brick sliding mechanism of the nacre-inspired structure with the phase transition energy dissipation mechanism of the shear-thickening material,and the structure and material cooperate with each other.The larger out-ofplane deformation of the nacre-inspired structure further increases the damage area energy dissipation of the shear-thickening sandwich layer,demonstrating excellent impact resistance performance over a wide range of impact veocities.In addition,further experimental studies have shown that the bio-inspired composite glass material has the characteristics of safety,lightweight,optical transparency,and thermal insulation performance.The proposed bio-inspired structural material design method achieves the synergistic effect between the bio-inspired structure and component materials,providing a new approach for designing high-performance bio-inspired structural materials.