Abstract In this study, a novel shear-lag model based on impregnated fiber bundle (IFB) element is developed to predict the tensile behavior of unidirectional fiber-reinforced polymer (FRP) composites. Rather than using a fiber element, the new model enables a full-field failure simulation due to its finite number of elements. Based on the micromechanical difference equation, we validated the effectiveness of the model and identified the damage evolution pattern by applying it to a basic model of 6 mm FRP tendon. Then, the effect of varied constituent properties, hybrid fibers and initial defects were investigated using the Monte Carlo (MC) method. Several interesting results were found and compared with the findings of earlier studies. For instance, it was found that a more stable IFB strength and higher matrix shear strength reduced variations in composite strength. A moderate hybrid ratio and careful packing of high- and low-elongation fibers helped to achieve optimum composite properties. In the thin-ply composite, transverse initial defects were more detrimental to composite strength than longitudinal defects. These findings prove the value of the bundle-based model, which can be used in future studies as an effective tool for evaluating the strength of various composites.

中文翻译：

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用于单向纤维增强聚合物复合材料拉伸失效预测的基于束的剪切滞后模型

摘要 在本研究中，开发了一种基于浸渍纤维束 (IFB) 元素的新型剪切滞后模型，以预测单向纤维增强聚合物 (FRP) 复合材料的拉伸行为。由于其元素数量有限，新模型没有使用纤维单元，而是可以进行全场故障模拟。基于微力学差分方程，我们验证了模型的有效性，并通过将其应用于6 mm FRP筋的基本模型来识别损伤演化模式。然后，使用蒙特卡罗 (MC) 方法研究了不同成分特性、混合纤维和初始缺陷的影响。发现了几个有趣的结果，并与早期研究的结果进行了比较。例如，发现更稳定的 IFB 强度和更高的基体剪切强度减少了复合材料强度的变化。适度的混合比和高、低伸长率纤维的仔细包装有助于实现最佳复合性能。在薄层复合材料中，横向初始缺陷比纵向缺陷对复合材料强度的影响更大。这些发现证明了基于束的模型的价值，可以在未来的研究中用作评估各种复合材料强度的有效工具。