Different failure mechanisms can lead to very different mechanical responses of notched composite laminates. We are trying to address two scientific problems: how can the occurrence of failure mechanisms be manipulated, and which kinds of failure mechanisms in open-hole tensile (OHT) tests can be manipulated to help improve the ultimate strength of composites? In this paper, three design strategies were proposed to manipulate the failure mechanism of notched composites: decreasing ply thickness at the ply level, hybridizing thin- and thick-ply laminates, and designing helical structures with variable pitch angles and ply thicknesses. Numerical methods are adopted to investigate the influence of the three design strategies on the failure mechanism of notched composites. These three design strategies are not limited to use in an OHT test. The results suggest effective methods for manipulating failure mechanisms to help create laminates with better mechanical properties.

不同的失效机制会导致缺口复合层压板的机械响应大不相同。我们正试图解决两个科学问题：如何操纵失效机制的发生，以及可以操纵开孔拉伸 (OHT) 测试中的哪些失效机制来帮助提高复合材料的极限强度？在本文中，提出了三种设计策略来操纵缺口复合材料的失效机制：在层级降低层厚度，混合薄层和厚层层压板，以及设计具有可变螺距角和层厚度的螺旋结构。采用数值方法研究了三种设计策略对缺口复合材料失效机理的影响。这三种设计策略不限于在 OHT 测试中使用。