Effect of ply-drop configuration on delamination strength of tapered composite structures
Effect of ply-drop configuration on delamination strength of tapered composite structures
复制标题
铺层配置对锥形复合材料结构分层强度的影响
DOI：
10.2514/3.13285
复制
发表时间：
1996
期刊：
影响因子：
--
通讯作者：
S. Lee
中科院分区：
文献类型：
--
作者：
Anthony D. Botting;A. Vizzini;S. Lee
通过改变层片滴落顺序来抑制分层，对锥形玻璃/环氧树脂层压板进行了评估。研究了两种不同的堆叠顺序，其薄片叠层为[0 4 /±45 2 ] s 和[±45 2 /0 4 ] s，其中包含三组±45 度层片的液滴。构建使用三维实体单元的有限元模型来评估帘布层下降内部和周围的层间应力状态。通过在自由边缘附近提供网格细化来考虑无应力边缘的影响。锥形样品是在准静态单轴拉伸下制造和测试的。对于[0 4 /±45 2 ] s 堆叠顺序的样本，分层强度取决于铺层下降顺序，并且铺层下降区域的结构调整会导致层间应力状态降低并相关的分层强度增加。然而，结构剪裁在 [±45 2 /0 4 ] 样本中似乎无效。尽管有限元模型显示出更强的敏感性，但测量的分层强度对铺层顺序不敏感。一般来说，有限元模型与数据有很好的相关性。 [0 4 /±45 2 ] s 样品之间的强度测量差异以及 [0 4 /±45 2 ] s 和 [±45 2 /0 4 ] s 样品之间的总体强度差异是通过有限元模型使用层间树脂区域应力状态的强度标准来预测的。
Delamination suppression by altering the sequence of ply drops is evaluated for tapered glass/epoxy laminates. Two different stacking sequences with thin section layups of [0 4 /±45 2 ] s and [±45 2 /0 4 ] s containing drops of three sets of ±45-deg plies are investigated. A finite element model using three-dimensional solid elements is constructed to evaluate the state of interlaminar stress in and around the ply drops. The effect of the stress-free edge is considered by providing a mesh refinement near the free edge. Tapered specimens are manufactured and tested under quasistatic uniaxial tension. For specimens of [0 4 /±45 2 ] s stacking sequence, delamination strength is dependent on the ply-drop sequence, and structural tailoring of the ply drop region results in a reduced interlaminar stress state and an associated increase in delamination strength. Structural tailoring, however, appears to be ineffective in the [±45 2 /0 4 ] s specimens. The measured delamination strengths are insensitive to the ply-drop sequence, although the finite element model indicates a stronger sensitivity. In general, the finite element model correlates well with the data. The measured differences in strength among the [0 4 /±45 2 ] s specimens and the overall strength difference between the [0 4 /±45 2 ] s and the [±45 2 /0 4 ] s specimens are predicted by the finite element model using strength criteria on the stress state in the interply resin region.