针刺复合材料层次化建模及弹性性能预测

In order to address the problem of complex structures such as random fiber layers in needled composites that make it difficult to assign periodic meshes， a periodic boundary condition imposition method for non-periodic meshes was developed based on the local radial point interpolation model (LRPIM). First， X-ray tomography tests were carried out to analyze the material microstructure，from which three typical characteristic structures of un-needling region， needling bypass region and needling through region were extracted. Subsequently， considering the complex composition of needled composites， a hierarchical modeling method based on multiple feature structures was proposed to decompose the complex microscopic feature structures into single material phases for refinement modeling，and homogenization by level was achieved to obtain the material’s elastic properties. Finally， the mechanical properties tests of the needled composites were carried out. The results showed that the prediction errors of the x-direction tensile modulus and in-plane shear modulus were 1.5% and 6.4%，respectively，which verified the accuracy of the proposed modeling approach.