结合改进单胞模型的单钉双剪层合板螺栓连接结构挤压性能的多尺度表征分析

为提高螺栓连接层合板结构的可靠性和承载能力,基于ABAQUS软件及用户子程序(USDFLD),结合改进的单胞模型,建立了考虑组分材料失效的多尺度数值模型。利用该模型表征分析了单钉双剪层合板螺栓连接结构的力学性能,研究了铺层形式及几何尺寸对连接结构性能的影响。该模型的预报结果与试验结果吻合较好。结果表明:准各向同性层合板螺栓连接结构的挤压强度高于正交各向异性层合板连接结构的挤压强度,前者的失效模式为挤压失效,后者为剪出失效,该模式导致结构承载能力降低,设计中应避免。层合板边径比大于3时,不同宽径比连接结构的挤压强度趋近稳定值;但相同边径比的连接结构,其挤压强度随宽径比的增大而增大,连接结构设计时应给予考虑。 

Multi-scale characterization analysis combined with improved cells model for bearing performance of double-shear single bolted joint laminate structures

In order to improve the reliability and load carrying capacity of bolted joint laminate structure, the multi-scale numerical model combining with improved cells model and considering the failure of constituent materials was created based on ABAQUS software and user subroutine (USDFLD). Based on the model, the mechanical properties of the double-shear single bolted joint laminate structures was characterized, and the effects of layup form and geometry on the properties of bolted joint structure were researched. The predicted results using the model were in good agreement with the testing results. The results show that the bearing strength of quasi-isotropic bolted joint laminate structure was higher than that of orthotropic bolted joint laminate structure, and the failure mode of the former was bearing failure, but that of the latter was shearing failure. The shearing failure will result in the decrease of structure bearing capacity. So it should be avoided during the design. When the ratio of edge to diameter for laminate is greater than 3, the bearing strength converges to a stable value for the bolted joint structure with different ratio of width to diameter. But as for the bolted joint structure with the same ratio of edge to diameter, the bearing strength increases with the increase of the ratio of width to diameter. It also should be given consideration during the process of bolted joint structure design.