缝合复合材料层板三维纤维弯曲模型及压缩强度预报

提出了三维纤维弯曲模型, 基于有限元法和周期性边界条件建立了缝合层板压缩强度分析方法, 采用桥联模型和最大应力判据分析损伤扩展并获得压缩强度, 预报结果与试验吻合较好。详细探讨了缝合参数对层合板压缩强度的影响规律, 结果表明: 缝合方向与表面纤维方向一致时, 较小的缝合针距和行距、较大的缝合线半径对压缩强度较为有利; 缝合方向与表面纤维方向垂直时, 较小的缝合针距和缝合线半径、较大的缝合行距对压缩强度较为有利。 

3D f iber waviness model and prediction of compressive strength of stitched laminates

A 3D fiber waviness model was presented. Based on the finite element method and periodic boundary conditions, a method to analyze the compressive strength of stitched laminates was established, which adopted a bridging model and maximum stress criteria to predict the development of damage and obtain the compressive strength. The predicted results are in good agreement with the test data. The effects of stitching parameters on the compressive strength of stitched laminates are discussed in detail. The results indicate that when stitching along the fiber on the surface of laminates, smaller stitch space and step and larger stitch radius result in higher compressive strength. However, when stitching perpendicular to the fiber on the surface, smaller stitch space and radius and larger stitch step result in higher compressive strength.