玻璃钢/复合材料 ›› 2019, Vol. 0 ›› Issue (2): 20-25.

• 基础研究 • 上一篇    下一篇

记及压应力的内聚力单元及其厚度对复合材料分层损伤预测的影响

郭双喜, 李雪芹   

  1. 航空工业复合材料技术中心,中航复合材料有限责任公司,先进复合材料重点实验室,北京101300
  • 收稿日期:2018-05-08 出版日期:2019-02-28 发布日期:2019-02-28
  • 作者简介:郭双喜(1989-),男,工程师,硕士,主要从事复合材料结构损伤方面的研究,guoshuangxi2012@126.com。
  • 基金资助:
    国家重点研发计划资助项目(2017YFB0703300);973项目(613245)

THE INFLUENCES OF COHESIVE ELEMENT COMPRESSIVE STRESS AND ITS THICKNESS ON DELAMINATION PREDICTION OF COMPOSITE

GUO Shuang-xi, LI Xue-qin   

  1. AVIC Composite Technology Center, AVIC Composite Corporation Ltd., National Key Laboratory of Advanced Composites, Beijing 101300, China
  • Received:2018-05-08 Online:2019-02-28 Published:2019-02-28

摘要: 内聚力单元可以同时预测分层的起始和扩展,但单元尺寸对计算结果影响较大,而且无法模拟压应力导致的界面失效。首先,建立不同内聚力单元计算厚度的双悬臂梁模型、端边加载模型和冲击动力学模型,模拟分层损伤演化过程,研究内聚力单元厚度对载荷-位移曲线和界面损伤面积的影响;然后,通过子程序自定义内聚力单元的本构关系,考虑压缩应力引起的复合材料层间界面失效;最后,分析考虑压应力引起的界面层失效对复合材料冲击响应的影响。计算结果表明:内聚力单元厚度对界面层的损伤面积影响明显;相同的载荷条件下,内聚力单元厚度越大,界面损伤面积越小;考虑压缩应力引起的界面层失效,界面损伤面积较大且界面失效包含压缩和剪切两种失效模式。

关键词: 分层, 内聚力单元, 单元厚度, 冲击, 损伤面积, 破坏模式

Abstract: To model the delamination initiation and propagation of the composite laminates, the cohesive element is often used. But, unfortunately, the numerical result may depend on element size, and it can′t model the interface failure caused by large compressive stress. Firstly, three models with different thickness of the cohesive element, i.e. the double cantilever beam model, the end-loaded split model and the dynamic impact model, are established to simulate the delamination evolution of the composite. The influences of the cohesive element thickness on the load-displacement curve and interface damage area are studied. Then, the constitutive relation of cohesive element is defined by the subroutine to consider the interface failure caused by compressive stress, and the impact of interface failure caused by compressive stress during impact response of composites is analyzed. The results show that the thickness of cohesive element has a significant influence on the interface damage area. Under conditions of the same loading, the damage area of the interface becomes smaller as the cohesive element thickness becomes larger. With the consideration of the interface layer failure caused by compressive stress, the interface damage area would be larger and the interface modes contains compression failure and shear failure.

Key words: delamination, cohesive element, element thickness, impact, damage area, failure mode

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