A contact extended isogeometric layerwise approach for the buckling analysis of delaminated composites
A contact extended isogeometric layerwise approach for the buckling analysis of delaminated composites
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DOI：
10.1016/j.compstruct.2014.05.006
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发表时间：
2014-09
影响因子：
6.3
通讯作者：
Yujie Guo;M. Ruess;Z. Gürdal
中科院分区：
文献类型：
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作者：
Yujie Guo;M. Ruess;Z. Gürdal
基于等几何分层方法研究了含分层损伤的复合材料层合板的屈曲问题。等几何方法采用几何描述的NURBS基函数来近似等参数意义上的物理响应。分层理论在保持二维数据结构的同时，提供了复合材料层合板的三维结构响应的精确预测。通常，通过厚度的脱层模型，位移场是丰富的单位阶跃海维赛德函数，允许在脱层界面处的不连续性。提出了一种基于等几何范式的基于位移的分层理论的改进实现。层合板的分层和未分层区域被建模为单独的补丁。对于未脱层和脱层两种情况，层间位移场的C0连续和不连续条件可以在等几何框架内得到简化。通过考虑脱层界面的接触分析，可以获得更可靠和准确的屈曲载荷，以避免物理上不允许的屈曲模式。采用复合材料层合梁板对所提出的模型进行了验证。结果进行了比较，一个经典的分层方法。数值结果证实了所提出的等几何模型的准确性。
Buckling of composite laminates with delaminations is studied based on a proposed isogeometric layerwise approach. The isogeometric approach employs the NURBS basis functions of the geometry’s description to approximate the physical response in an isoparametric sense. Layerwise theories provide an accurate prediction of the three-dimensional structural responses of composite laminates while maintaining a two-dimensional data structure. Usually, to model the delaminations through thickness, the displacement field is enriched with a unit step Heaviside function which allows for discontinuities at the delamination interfaces. An improved implementation of a displacement-based layerwise theory based on the isogeometric paradigm is proposed. The delaminated and undelaminated regions of the laminate are modeled as separate patches. For the undelaminated and delaminated patches respectively, the C 0-continuity and discontinuity conditions of the displacement field at the ply interfaces can be easily facilitated within the isogeometric framework. More reliable and accurate buckling loads are obtained by considering a contact analysis across the delamination interfaces to avoid physically inadmissible buckling modes. The proposed model is verified using laminated composite beam plates. The results are compared to a classical layerwise approach. The numerical results confirm the accuracy of the proposed isogeometric model.