缝合复合材料层板面内局部纤维弯曲模型及刚度预报

提出了缝合层板面内局部纤维弯曲模型,假设缝合线受挤压后横截面为椭圆形,指出当纤维弯曲幅度较小时,缝合仅造成单胞内局部纤维弯曲,纤维弯曲角为特定值,由纤维种类决定;当纤维弯曲幅度较大时,缝合造成单胞内整体纤维弯曲,纤维弯曲角大于特定值,由纤维弯曲幅度和单胞尺寸决定。采用有限元法建立了缝合层板刚度分析方法,使缝合层板单胞满足周期性边界条件,预报结果与试验吻合较好,详细探讨了缝合参数对层板刚度的影响规律,结果表明缝合后层板刚度降低,缝合参数变化对层板刚度有较大影响。

In-Plane Local Fiber Waviness Model and Stiffness Prediction for Stitched Laminates

In-plane local fiber waviness model of stitched laminates is presented under the assumption that the cross section of extruded stitch gets elliptical.The model pointed out that fiber waviness caused by stitching is limited within the unit cell of stitched laminates as amplitude of the waviness is slight,and the fiber reaches to bevel waviness a specific value depending on fiber type.While the fiber waviness is great enough,fiber waviness unit cell of stitched laminates,and the fiber bevel determined by the size of unit cell and the amplitude of fiber waviness gets beyond the specific value.The effects of stitching parameters on stiffness of stitched laminates are discussed in detail. The results indicate that stitching reduces laminate the stiffness and stitching parameters exert obvious effects on the laminate stiffness.