CAREER: Damage Evolution in Polymeric Materials undergoing Hydrolysis or Photo-Degradation

该学院早期职业发展（CAREER）计划支持基础研究，通过促进对聚合物中化学反应和机械变形对降解（材料损伤演变）的综合影响的理解来改善国家的健康。作为一个例子，对于修复断裂的骨，对不断发展的损伤的了解决定了聚合物生物医学植入物如何能够提供适当的支撑并在断裂的骨愈合的同时降解和吸收到体内。目前，设计工程师缺乏预测可降解聚合物组件的承载能力所需的信息，因此，设计不是最佳的。 这项研究的结果将产生实验数据，数学模型和模拟工具，将揭示聚合物材料的降解行为的化学成分和施加的负载之间的关系。这些知识将使在许多应用中，聚合物降解发生的工程设计得到改进，从而促进国家的繁荣和福利沿着科学进步。该提案包括一个由几个组成部分组成的综合教育计划，其中之一是为NJIT的本科生和研究生开发新课程。课程材料也将被修改，并通过大学范围内的倡议适应到大学预科生的推广计划。本研究的目的是弥合行为知识差距目前限制我们的预测能力的聚合物材料进行降解反应，由于水解或光降解。因此，提出了以下研究任务：（i）发展一对物理一致的，帧无关的，实验验证的多物理本构理论的软材料进行水解和光降解反应的行为。(ii)对工业上重要的和智力上刺激的聚合物PLA进行实验，在专门探测化学和力学之间的耦合的条件下，以支持结构性工作和验证目的。(iii)耦合大变形隐式固体力学与反应扩散系统和辐射传递的一组新的鲁棒有限元公式。(iv)研究和教育的整合，培养和激发各级学生的兴趣，从大学预科到研究生院。 这个项目将允许PI推进多场效应下材料力学的知识基础？从建模到计算？该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This Faculty Early Career Development (CAREER) program supports fundamental research to improve the Nation's health by advancing the understanding of the combined effect of chemical reactions and mechanical deformation on degradation (material damage evolution) in polymers. As an example, for repairing broken bone, knowledge of the evolving damage determines how the polymeric biomedical implant can provide proper support and commensurately degrade and absorb into the body, while a broken bone heals. Currently design engineers lack the information necessary to predict the load carrying capacity of degradable polymeric components and, therefore, the designs are not optimal. The results of this research will generate experimental data, mathematical models, and simulation tools that will uncover the relationship between chemical constituents and applied load on the degradation behavior of polymeric materials. That knowledge will enable improved engineering design in numerous applications where polymeric degradation occurs, thus advancing national prosperity and welfare along with scientific progress. The proposal includes an integrated education plan with several components, one of which is the development of new courses for undergraduate and graduate students at NJIT. The course material will also be modified and adapted into outreach programs for pre-college students through university-wide initiatives.The objective of this research is to bridge the behavioral knowledge gap currently limiting our predictive ability for polymeric materials undergoing degradation reactions due to hydrolysis or photo-degradation. Accordingly, the following research tasks are proposed: (i) Development of a pair of thermodynamically consistent, frame-indifferent, experimentally validated multiphysics constitutive theories for the behavior of soft materials undergoing hydrolysis and photo-degradation reactions. (ii) Experimentation on the industrially important and intellectually stimulating polymer PLA, under conditions that specifically probe the coupling between chemistry and mechanics in support of the constitutive effort and for validation purposes. (iii) Formulation of a new set of robust finite elements that couple large deformation implicit solid mechanics with reaction-diffusion systems and radiative transfer. (iv) Integration of research and education to train and spark interest in students of all levels, from pre-college to graduate schools. This project will allow the PI to advance the knowledge base in mechanics of materials under multiple field effects?from modeling to computation?and establish a long-term career in mechanics.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.