This work mainly investigates the effects of the hole number and layer direction on the tensile mechanical behavior and failure mechanisms of multihole fiber metal laminates by experimental and numerical methods. With the aid of digital image correlation technique, tensile tests are implemented to obtain mechanical responses of different multihole fiber metal laminates. Subsequently, numerical simulation considering thermal residual stress is conducted to elucidate the failure modes and progressive damage evolution of multihole fiber metal laminates, which integrates the progressive damage model of composite laminates and a cohesive zone model between aluminum sheet/composite laminates. Finally, numerical predictions are found in a good agreement with experimental measurements, in terms of mechanical responses and fracture morphologies. Results demonstrate that the number of holes has negligible influence on the ultimate tensile strength, whereas affects the final failure strain of multihole fiber metal laminates evidently. With the increase of layer direction, the fracture morphology changes from evident brittle fracture to fiber pull-out and matrix damage, which indicates that the critical failure mechanism of multihole fiber metal laminates changes from tension dominated to tension–shear dominated. Additionally, the longer loading history from initial damage to final failure of composite laminates demonstrates the significance of considering progressive damage behavior in numerical simulation.

中文翻译：

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多孔纤维金属层压板的拉伸力学行为和失效机制——实验表征和数值预测

本工作主要通过实验和数值方法研究孔数和层向对多孔纤维金属层压板的拉伸力学行为和失效机制的影响。借助数字图像相关技术，进行拉伸试验以获得不同多孔纤维金属层压板的力学响应。随后，通过考虑热残余应力的数值模拟，阐明了多孔纤维金属层压板的失效模式和渐进式损伤演化，该过程集成了复合层压板的渐进损伤模型和铝板/复合层压板之间的内聚区模型。最后，在力学响应和断裂形态方面，数值预测与实验测量结果非常吻合。结果表明，孔数对极限抗拉强度的影响可以忽略不计，而对多孔纤维金属层压板的最终破坏应变有明显的影响。随着层向的增加，断裂形态由明显的脆性断裂转变为纤维拉出和基体破坏，这表明多孔纤维金属层压板的临界破坏机制由张力主导转变为张力剪切主导。此外，复合材料层压板从初始损坏到最终失效的较长加载历史证明了在数值模拟中考虑渐进式损坏行为的重要性。随着层向的增加，断裂形态由明显的脆性断裂转变为纤维拉出和基体破坏，这表明多孔纤维金属层压板的临界破坏机制由张力主导转变为张力剪切主导。此外，复合材料层压板从初始损坏到最终失效的较长加载历史证明了在数值模拟中考虑渐进式损坏行为的重要性。随着层向的增加，断裂形态由明显的脆性断裂转变为纤维拉出和基体破坏，这表明多孔纤维金属层压板的临界破坏机制由张力主导转变为张力剪切主导。此外，复合材料层压板从初始损坏到最终失效的较长加载历史证明了在数值模拟中考虑渐进式损坏行为的重要性。