复合材料紧固件拉脱试验与数值仿真研究

Numerical and Experimental Study on Pull off Failure Behaviors of Composite Fasteners

为了获得复合材料紧固件在拉脱载荷下的性能,同时进行了试验与有限元仿真研究。通过与试验结果对比,验证了有限元模型的有效性,获得了能真实反映结构破坏的失效模式和位移载荷曲线。仿真得到的破坏载荷与试验的偏差为-3.34%。在有限元模型的基础上对不同长短轴椭圆间隙孔边界的紧固件进行了研究,结果表明间隙孔边界主要影响紧固件的刚度,当椭圆长短轴a/b从1变化到1.5时,破坏载荷下降了3.61%,而破坏位移增大了28.51%。除此之外对一定孔径比下铆钉直径的影响也展开了分析,铆钉直径的增大能略微提高其极限载荷,当其为5.5mm和6mm时相对于为5mm时分别提高了4.45%和8.06%。

In order to obtain the properties of composite fasteners under pull off load,the experiments and finite element simulation were carried out simultaneously in this paper.Compared with the experimental results,the validity of the finite element model is verified,and the failure modes and displacement load curves which can reflect the structural failure areacquired.The deviation of ultimate load between numerical and experimental results is-3.34%.Based on the finite element model,the fasteners with different boundary of elliptic clearance holes were investigated.The results show that the boundary of clearance holes mainly affects the stiffness of fasteners.When the ratio of the major axis to the minor axis a/b of elliptic clearance holes changes from 1 to 1.5,the ultimate load decreases by 3.61%and the failure displacement increases by 28.51%.In addition,the influence of rivet diameter under a certain aperture ratio was also studied.The increase of rivet diameter has slightly influence on the ultimate load,and when the rivet diameter is 5.5mm or 6mm,the ultimate load increases 4.45%and 8.06%,respectively,compared with 5 mm.