缝合复合材料弹性性能分析的新方法——流场模型Ⅰ:缝合单层板弹性常数计算

New method on the elastic properties of stitched composites——Flow field model Ⅰ: Elastic constants calculation of the stitched laminar

为了求解缝合层合板中单层的弹性常数,基于单层面内纤维走向与绕流流场中流线形状的相似性,建立了与缝合单胞相对应的有限空间定常二维无粘性不可压理想流体的无旋绕流流场模型,流场的几何边界与单胞的边界一致,绕流物面与缝线截面形状一致。用该流场的速度变化描述单胞面内纤维体积含量的变化,用流线形状描述缝线周围面内纤维的变形。以流场模型为基础,用细观力学方法和均匀化方法求得缝合单层的弹性常数,结果与实验值吻合。最后用流场模型分析了缝合参数对缝合单层弹性常数的影响。

Based on the similarity between the orientation of the fiber in the stitched laminates and the stream in the flow around a cylinder, a flow field model is built for the elastic constants of the stitched laminar, which is a steady 2D non-compressible non-viscous ideal flow without swirl in a finite space. The boundaries of the flow field and the unit cell of the stitched laminates are identical, and the surface of the body in the flow field is the same as the section shape of the stitch thread. The velocity variation in the flow field describes the fiber volume fraction variation in the unit cell of the stitched laminar, and the streamline shape describes the fiber orientation. Using the flow field model, the elastic properties of the stitched laminar are calculated by the micromechanics and the homogenization method, and the results are in good agreement with those of the test. Finally, the effects of the stitch parameters on the laminar elastic constants are discussed.