间隙补偿及液体垫片参数对层合板单层与层间应力的影响
Effect of Gap Compensation and Parameters of Liquid Shim on Composite Laminates Internal Stress and Interlaminar Stress

在飞机装配中，一般采用液体垫片对复合材料层合板构件之间较小的装配间隙进行补偿。以复合材料层合板机械连接中典型的单螺栓连接为对象，考虑强迫装配（未实施间隙补偿）与采用液体垫片实施间隙补偿两种情况，设计了层合板应变测量实验；其次，利用ABAQUS建立有限元模型并进行计算验证，有限元模型计算结果与实验测量数据的吻合度较好。根据建立的模型，研究了间隙补偿及不同液体垫片参数下，层合板的单层面内应力与层间应力的变化。有限元分析结果表明：相对于强迫装配，随着间隙的增大，液体垫片对于改善层合板的应力分布、减小应力幅值、增强抗分层能力的作用愈加显著；三代液体垫片对层合板各单层面内应力与层间应力的影响差异非常微小；大幅增加垫片弹性模量后，单层面内应力的影响效果将明显提升。
In general, the liquid shim is used to compensate the small gaps between the composite components in the aircraft assembly. The single bolt connection of composite laminates as the object, one experiment were designed:the measurement of the strain of laminated plate, and two cases are considered in the process:using a liquid shim to compensate for the gap and without it; The finite element model was built and validated by using ABAQUS software. The calculation results are in a good agreement with the experimental. Under different liquid shim compensation parameters, the change in the stress of laminated plate, including laminates internal stress and interlaminar stress are studied based on the present model. The results show that:with the increasing of gap, the liquid shim is more significant to improve the stress distribution, reduce the stress amplitude, and enhance the ability to resist delamination; the three generations liquid shim have very little differences on laminates internal stress and interlaminar stress; laminates internal stress will be significantly improved if a substantial increase in the elastic modulus of the shim