Investigation of composite filled hole coupons and lockbolt fastened joints under impact loading
Investigation of composite filled hole coupons and lockbolt fastened joints under impact loading
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DOI：
10.1007/s00419-016-1125-9
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发表时间：
2016-03
影响因子：
2.8
通讯作者：
N. Perogamvros;G. Lampeas
中科院分区：
文献类型：
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作者：
N. Perogamvros;G. Lampeas
使用有效的建模技术研究了承受冲击拉伸载荷的两种不同的复合材料紧固结构，即填充孔和单搭接双紧固件接头。采用“堆叠壳”方法（或“2.5D”方法）的新颖模拟方法，以便使用非线性显式动力学有限元代码 LS-DYNA 对紧固复合材料试样进行建模。在堆叠壳方法中，复合板由壳单元的离散子层压板表示，这些壳单元使用具有粘性区域属性的界面单元连接在一起，从而形成一种计算有效的方法来解决涉及严重层间和层内材料失效的问题。数值模型根据相关实验测试数据进行验证，这些数据源自在研究的冲击载荷范围内进行的实验。仿真结果表明，该模型能够以极高的精度预测损坏的发生、失效模式和紧固样本的载荷-位移响应。此外，数值研究表明，两种检查配置的强度值对加载速率的敏感性有限，而搭接接头样本表明，随着加载速率的增加，最终失效模式发生显着变化。
Two different composite fastened configurations, i.e., the filled hole and the single-lap double-fastener joint, subjected to impact tensile loads, are investigated using efficient modelling techniques. The novel simulation methodology of the ‘stacked shell’ approach (or ‘2.5D’ approach) is exploited, in order to model the fastened composite coupons using the nonlinear explicit dynamics finite element code LS-DYNA. In the stacked shell approach, the composite plates are represented by discrete sublaminates of shell elements, which are tied together using interface elements with cohesive zone properties, resulting in a computationally efficient methodology of solving problems that involve significant inter-ply and intra-ply material failure. The numerical models are validated against relative experimental test data, derived from experiments which are performed within the investigated impact loading regime. The simulation results demonstrate that the models are capable to predict the onset of the damage, the failure modes and the load–displacement response of the fastened specimens with notable accuracy. In addition, the numerical investigation has shown limited loading rate sensitivity in terms of strength values for both of the examined configurations, while the lap joint samples illustrate pronounced changes in the final failure mode as the loading rate increases.