Biomimetic Construction of CPC Foam Microstructure and Its Compressive Mechanical Properties
Conductive polymer composite(CPC)foam exhibits excellent characteristics such as high plasticity,energy absorption,as well as thermal and acoustic insulation,and holds enormous potential for applications in various fields including construction,transportation,electronics,etc.However,the porous structure of CPC foam is usually simple and random,which limits its further application.The complexity of CPC processing makes it challenging to achieve a controlled design of micro-porous structures.Inspired by the idea that biomaterials can enhance their mechanical properties by virtue of their well-aligned aniso-tropic microstructures,highly aligned anisotropic porous biomimetic microstructures are constructed by a bidirectional freeze-casting process to enhance the compressive mechanical properties of CPC foam.Com-pared to traditional unidirectional freezing,the compressive elastic modulus and peak stress of aligned ani-sotropic porous microstructured CPC foam increase by 18.7％and 25.4％,respectively.Buckling and col-lapsing risks during cyclic compression are significantly reduced,and a peak stress of 91.1％and a strain recovery of 89.6％are still maintained after 2,000 cycles at 50％strain.A finite element model of the por-ous structure in CPC foam is built with parameters including elastic modulus,hole wall thickness,and Poisson's ratio,obtained from measured data or literature.The quasi-static compressive behaviors of bio-mimetic and disordered structures are investigated using the finite element method,and the deformation and stress distribution are compared with the corresponding experimental results.Through finite element simulations and experimental tests,it is found that the main mechanisms enhancing the compressive me-chanical properties of the materials are as follows:stress distribution optimization effectively prevents plas-tic deformation caused by local stress concentration;the highly elastic behavior of micrometer pore wall and its 3D structure enhance the bionic structure's resilience;and the highly aligned anisotropic channels provide ample deformation space,improve deformation coordination,and enhance the structure's reversi-bility during loading and unloading.
万方数据
维普
