基于四胞元模型的3D缝合复合材料力学性能预测

Mechanical property prediction for 3D stitched composites based on four-cell models

  • 摘要: 3D缝合复合材料纤维结构复杂,缝合区域微结构存在不确定性。提出3D缝合复合材料的虚拟纤维建模方法,通过模拟缝合成形工艺,生成缝合部位的高保真度几何孪生模型。利用Micro-CT技术分析缝合部位纤维结构,验证了几何孪生模型的准确性。考虑缝合结构的不确定性,提出四种代表性几何结构,采用虚拟纤维嵌入(VFE)技术,将虚拟纤维结构与基体材料体素单元嵌入耦合,构造了3D缝合复合材料四种胞元模型。针对纤维和基体材料分别建立损伤模型,模拟3D缝合复合材料拉伸损伤过程,预测了不同缝合部位的力学性能。四种胞元模型预测结果的平均值与实验结果相一致,拉伸强度、模量和破坏应变的预测误差分别为1.5%、1.2%和0.4%。

     

    Abstract: The fiber structure of 3D stitched composites is complex and the microstructure of stitched area is uncertain. A virtual fibre modelling method for 3D stitched composites was proposed to generate a high-fidelity geometric twin model of the stitched position by simulating the stitching manufacturing process. Micro-CT technique was used to analyze the fiber structure of the stitched position, and the accuracy of the geometric twin model was verified. Considering the uncertainty of the stitching structure, four representative geometrical structures were proposed, four-cell models of 3D stitched composites were constructed using virtual fiber embedded (VFE) method, in which the virtual fiber structures were embedded into voxel elements representing matrix material. Damage models were established for fiber and matrix materials to simulate the tensile damage process of 3D stitched composites, and the mechanical properties of different stitched positions were predicted. The average values of the predicted results of the four-cell models are consistent with the experimental results, and the prediction errors of tensile strength, modulus and damage strain are 1.5%, 1.2% and 0.4%, respectively.

     

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