CAREER: Curing-Induced Microcracking in Thermoset Composites

职业：热固性复合材料中固化引起的微裂纹

• 批准号: 2145387
• 负责人: Marianna Maiaru
• 金额: $ 56.83万
• 依托单位: University of Massachusetts Lowell
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2027-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2145387&HistoricalAwards=false
• 关键词: CAREER; Curing; Induced; Microcracking; Thermoset

This Faculty Early Career Development (CAREER) award enables contribution of new knowledge related to the manufacturing process for thermoset composite structures. Thermosets are advanced polymers that can be reinforced with high-strength fibers to create lightweight composite materials with complex architectures. Their manufacturing process involves chemical curing reactions, heat generation, and heat conduction that result in a change of phase from a liquid polymer mixture to a cross-linked solid structure. Stresses built up during the process can cause very small cracks to be formed, which can contribute to subsequent failures in the structure. Extensive curing-induced microcracking is a key technological challenge in the production of critical structural components for space exploration, wind energy production, and current and future transportation. The manufacturability of the next generation of high-performance, lightweight structures depends upon fabricating damage-free complex composites with enhanced mechanical properties. This award supports fundamental computational and experimental research to provide the necessary knowledge for developing crack-free thermosets, optimizing composite performance, and reducing the time and cost to create better composite parts. This research program will be integrated with educational and outreach activities, including developing an e-learning platform with engaging learning activities, K12 summer programs, and internships that aim to broaden the participation of underrepresented groups in research and positively impact engineering education. The research goal of this project is to reveal the fundamental mechanisms of curing-induced microcracking in thermoset composites. This project will establish process-property relationships to predict curing-induced damage mechanisms in thermosets across the micro and macro scales, which will enable new manufacturing capabilities. Knowledge generated from this research will allow manufacturers to tailor their processes to prevent curing-induced damage. This project will test the hypothesis that layer/layer and fiber/matrix property mismatches and resin shrinkage cause microcracking when the material is processed below its glass transition temperature and after gelation, depending on the resin viscosity and toughness. Advanced multiscale process modeling techniques that account for thermal gradients, resin exothermic reactions, mismatch in thermomechanical properties, shrinkage, and residual stresses will be implemented. A new time-independent characterization technique for determining material properties at intermediate degrees of cure based on off-stoichiometry polymer proxies will be tested. This novel approach to learning constitutive relations of thermosets during curing will be used to identify and quantify viscoelastic and viscoplastic resin properties during manufacturing. In-situ testing during curing will aim to validate the approach for three material systems, including 3D woven textiles, bonded adhesives, and thermosets for additive manufacturing. The planned result is an experimentally-validated physics-based multiscale process modeling framework to design and optimize enhanced composites which can help the composite industry by providing a missing link between material, manufacturing, and properties in order to prevent microcracking.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

这项教师早期职业发展（职业）奖可以贡献与热固性复合结构制造过程相关的新知识。热固性是高级聚合物，可以用高强度纤维加固，以创建具有复杂架构的轻质复合材料。它们的制造过程涉及化学固化反应，热量产生和热传导，从而导致相位从液体聚合物混合物变为交联的固体结构。在此过程中建立的压力会导致非常小的裂纹形成，这可能导致结构的随后故障。广泛的固化引起的微裂纹是生产用于太空探索，风能生产以及当前和未来运输的关键结构组件的关键技术挑战。下一代高性能，轻质结构的生产性取决于制造具有增强机械性能的无损害复合物。该奖项支持基本的计算和实验研究，以提供开发无裂纹的热固体，优化复合性能并减少创建更好复合零件的时间和成本的必要知识。该研究计划将与教育和外展活动相结合，包括开发具有吸引人的学习活动，K12夏季计划以及实习的电子学习平台，旨在扩大代表性不足的团体参与研究和积极影响工程教育。该项目的研究目标是揭示热固性复合材料中固化诱导的微裂纹的基本机制。该项目将建立流程 - 培训关系，以预测整个微型和宏观尺度的热眠器中固化引起的损伤机制，这将使新的制造能力。这项研究产生的知识将使制造商可以量身定制其过程，以防止固化引起的损害。该项目将检验以下假设：当材料在其玻璃过渡温度以下以及凝胶化后（根据树脂的粘度和韧性方面）处理材料时，层/层和纤维/矩阵特性不匹配和树脂收缩会导致微裂纹。高级多尺度过程建模技术将实施热梯度，树脂放热反应，热机械性能不匹配，收缩和残留应力。将测试一种新的独立于时间独立的表征技术，用于根据基于岩石计量的聚合物代理确定基于中等程度的材料特性。这种新颖的方法在固化过程中学习热固体的本构关系将用于识别和量化制造过程中粘弹性和粘塑性树脂特性。固化过程中的原位测试将旨在验证三种材料系统的方法，包括3D机纺织品，粘合粘合剂和用于添加剂制造的热固性。计划的结果是一个基于实验验证的多尺度过程建模框架，以设计和优化增强的复合材料，可以通过在材料，制造业和特性之间提供缺少的联系来帮助该复合行业，以防止微型opracking。该奖项反映了NSF的法定任务，并通过评估了基金会的智力效果，并通过评估了基金会的范围。

项目成果

PROGRESSIVE DAMAGE ANALYSIS OF STEEL-REINFORCED CONCRETE BEAMS USING HIGHER-ORDER 1D FINITE ELEMENTS

使用高阶一维有限元的钢筋混凝土梁渐进损伤分析

• DOI: 10.1615/intjmultcompeng.2022045649
• 发表时间: 2023
• 期刊: International Journal for Multiscale Computational Engineering
• 影响因子: 1.4
• 作者: Nagaraj, Manish H.;Maiaru, M.
• 通讯作者: Maiaru, M.

ANALYTICAL MODEL FOR COMPOSITE TRANSVERSE STRENGTH BASED ON COMPUTATIONAL MICROMECHANICS

基于计算微观力学的复合材料横向强度解析模型

• DOI: 10.1615/intjmultcompeng.2023048428
• 发表时间: 2023
• 期刊: International Journal for Multiscale Computational Engineering
• 影响因子: 1.4
• 作者: Shah, Sagar P.;Maiarù, Marianna
• 通讯作者: Maiarù, Marianna