Sajid Zubair, Karuppanan Saravanan, Eng Kee Kok, Shah Syed Zulfiqar Hussain
Department of Mechanical Engineering, College of Electrical and Mechanical Engineering, National University of Sciences and Technology, Islamabad 44000, Pakistan.
Mechanical Engineering Department, Universiti Teknologi PETRONAS, Seri Iskandar 32610, Perak, Malaysia.
Materials (Basel). 2023 Mar 9;16(6):2213. doi: 10.3390/ma16062213.
In recent years, there has been an increasing interest in open-hole and filled-hole laminate failure analysis. The open and filled-hole laminate failure analysis is used in several important areas, especially in designing mechanically fastened composite joints. Various analytical, empirical, and numerical methods are available for the design of mechanically fastened composite joints. The large number of material and geometrical design variables at the preliminary design stage makes the empirical and numerical methods effortful, expensive, and time-consuming. Therefore, analytical methods are recommended over numerical and empirical methods at the preliminary design stage merely because of their simplification in calculations, making them computationally efficient. Taking this into consideration, current research presents an improvement to the analysis capabilities of the previously introduced analytical method, i.e., the coupled approach of Classical laminate theory (CLT) and Lekhnitskii solutions. These improvements include the development of failure envelops for the open-hole and filled-hole laminates, estimation of optimized filling material for attaining maximum load-bearing capacity of filled-hole laminates, and optimization of stacking sequence for maximum load-bearing capacity of open-hole and filled-hole laminates. From the failure envelop results, it was found that failure envelopes of filled-hole laminates are bigger than open-hole laminates. Furthermore, it was found that the stiffness of the filling material should be equal to the stiffness of the laminate to achieve maximum bearing strength of the filled-hole laminate. It was also demonstrated that the coupled approach of CLT and Lekhnitskii solutions may provide carpet plots that can be utilized to optimize the stacking sequence for open-hole and filled-hole laminates.
近年来，人们对开孔和填孔层压板失效分析的兴趣日益浓厚。开孔和填孔层压板失效分析应用于多个重要领域，特别是在机械连接复合材料接头的设计中。机械连接复合材料接头的设计有多种分析、经验和数值方法。在初步设计阶段，大量的材料和几何设计变量使得经验和数值方法费力、昂贵且耗时。因此，在初步设计阶段推荐使用分析方法而非数值和经验方法，仅仅是因为其计算简化，使其计算效率高。考虑到这一点，当前的研究对先前引入的分析方法，即经典层压板理论（CLT）和列赫尼茨基解的耦合方法的分析能力进行了改进。这些改进包括开发开孔和填孔层压板的失效包络线，估计用于获得填孔层压板最大承载能力的优化填充材料，以及优化开孔和填孔层压板最大承载能力的铺层顺序。从失效包络线结果发现，填孔层压板的失效包络线比开孔层压板的大。此外，发现填充材料的刚度应等于层压板的刚度，以实现填孔层压板的最大承载强度。还证明了CLT和列赫尼茨基解的耦合方法可以提供地毯图，可用于优化开孔和填孔层压板的铺层顺序。
