Multiscale Modeling of Water Absorption and Mechanical Strength of Polymer Matrix Composite Materials Containing Voids

含空隙聚合物基复合材料吸水率和机械强度的多尺度建模

• 批准号: 1562062
• 负责人: Sarah Du
• 金额: $ 39.97万
• 依托单位: Florida Atlantic University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2020-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1562062&HistoricalAwards=false
• 关键词: Multiscale; Modeling; Water; Absorption; Mechanical

This award supports an investigation into water transport in composite materials containing voids due to direct contact with liquid water, and the associated degradation of the performance of the material. The potential degradation of the matrix polymer and the interface will be measured and the test data will be used to calibrate models for such degradation. Polymer matrix composite materials are used in structural applications exposed to water. As polymer matrix composite materials are gaining wide acceptance for several important structures, there has been concern about possible degradation of the performance from exposure to moisture in the form of humid air. Less considered is the influence of direct contact of the composite with liquid water. Such exposure under the presence of voids in the composite may allow water transport in the form of capillary flow. Capillary flow represents a very rapid mechanism of transport which will elevate diffusion into the polymer, and cause increased rate of degradation of the organic polymer and fiber/matrix interface. A substantial fraction of the US export and economy relies on the automotive, aircraft and ship building industries, and results from this research will benefit the US economy and society. This research involves multiple disciplines such as microfluidics, materials science and solid mechanics. The multi-scale approach outlined will involve students from underrepresented groups in science and engineering, and is expected to impact the engineering education program in a very positive manner.Voids and porosity are detrimental structural imperfections in polymer matrix composite materials, not only due to strength reduction, but they provide extra paths for water absorption and filling beyond moisture diffusion in matrix. This project specifically addresses the fundamental problems of the interferences between structural defects, moisture uptake, and mechanical strength and fracture mechanisms of underwater composite materials. Specific objectives are: (1) quantify structural defects in composite materials using scanning electron microscope and micro-computed tomography methods, establish a reliable water uptake model and validate with microfluidics testing; (2) characterize the fiber/matrix interface strength of dry and water-aged composite materials, using in situ scanning electron microscopy on miniature transverse single-fiber and composite tensile specimens; (3) establish a multiscale micromechanical model for prediction the strength of a macroscopic composite exposed to water aging. Predictions will be compared to and validated by the experimental measurements for water-aged glass/vinylester and glass/epoxy composites.

该奖项支持对由于与液态水直接接触而含有空隙的复合材料中的水传输以及材料性能的相关退化进行调查。 将测量基质聚合物和界面的潜在降解，并将使用试验数据校准此类降解的模型。聚合物基质复合材料用于暴露于水的结构应用中。随着聚合物基质复合材料在几种重要结构中获得广泛接受，人们一直担心暴露于潮湿空气形式的水分可能导致性能下降。较少考虑的是复合材料与液态水直接接触的影响。 在复合材料中存在空隙的情况下的这种暴露可以允许水以毛细流动的形式传输。毛细流动代表了一种非常快速的输送机制，其将提高向聚合物中的扩散，并导致有机聚合物和纤维/基质界面的降解速率增加。美国出口和经济的很大一部分依赖于汽车，飞机和造船业，这项研究的结果将有利于美国经济和社会。这项研究涉及微流体、材料科学和固体力学等多个学科。 所概述的多尺度方法将涉及来自科学和工程领域代表性不足的群体的学生，预计将以非常积极的方式影响工程教育计划。空隙和多孔性是聚合物基复合材料中有害的结构缺陷，不仅是由于强度降低，而且它们为基质中的水分扩散提供了额外的吸水和填充路径。该项目专门解决水下复合材料的结构缺陷，水分吸收，机械强度和断裂机制之间的干扰的基本问题。具体目标是：（1）利用扫描电子显微镜和微计算机断层扫描方法量化复合材料中的结构缺陷，建立可靠的吸水模型并通过微流体测试进行验证;（2）利用微型横向单纤维和复合材料拉伸试样的原位扫描电子显微镜表征干燥和水老化复合材料的纤维/基体界面强度;（3）建立了宏观复合材料水老化强度预测的多尺度细观力学模型。预测将进行比较，并验证水老化玻璃/乙烯基酯和玻璃/环氧树脂复合材料的实验测量。