基于失效机制的单向纤维增强树脂复合材料退化模型基于失效机制的单向纤维增强树脂复合材料退化模型

Failure mechanisms based degradation model of unidirectional fiber reinforced polymer composites

  • 摘要: 基于复合材料力学理论和失效机制,建立了一种新的适用于单向纤维增强树脂基复合材料的突降退化模型,用于描述复合材料基本材料性能在不同模式失效发生后的衰减行为。在模型中不仅考虑了复合材料拉伸和压缩弹性模量的差别,还考虑了损伤后材料拉伸和压缩性能退化的不同,以及裂纹闭合效应和侧向约束对压缩失效后性能的影响。另外,该模型只需要基本材料参数作为输入,便于应用。为了验证所提出的模型,建立了T800碳纤维增强X850环氧树脂基复合材料的退化模型,并对典型复合材料螺栓连接结构的拉伸失效行为进行渐进损伤分析。数值模拟获得的结构破坏载荷、破坏形式及载荷位移曲线与试验结果有较好的一致性,验证了所提出模型的计算精度和有效性。

     

    Abstract: Based on the failure mechanisms and mechanics of composite, a new degradation model for unidirectional fiber reinforced polymer composites was established to describe the degradation behavior of different failure modes. The difference between the tensile and compressive modulus, the different degradation of damage on the tensile and compressive modulus, the crack closure and the influence of the lateral supports were considered in the proposed model. The proposed model is convenient to use because only fundamental material properties are required. The degradation model for T800/X850 carbon fiber/epoxy composite was established and the progressive failure analyses of typical bolted composite joints were performed. The numerical predictions of failure load, failure patterns, and load-displacement curve were compared with results obtained from static tests. Good agreements between numerical failure predictions and experimental outcomes indicate the effectiveness and suitability of the proposed model.

     

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