NSF Young Investigator

小行星9458061 研究了复合材料失效的微观力学问题。 激光拉曼光谱（LRS），它可以测量应变和相位变化与2微米的空间分辨率，和X射线应力分析是主要使用的工具。 羟基磷灰石（HA）是一种存在于牙齿和骨骼中的陶瓷材料，本身易碎，作为一种人造材料，仅限于非结构应用。 使用LRS研究了氧化锆对HA的增韧，并将转变区绘制为载荷、暴露于生理溶液和氧化锆体积分数的函数。 已知水和有机环境降低石墨/环氧复合材料的机械性能。 暴露过程中界面的退化是复合材料失效的主要机制。 采用LRS监测界面的完整性，作为溶剂极性、温度和时间的函数。 在追求计算机辅助教学技术，适当的硬件和软件将开发用于聚合物教育。 这项研究应有助于发展复合材料系统的结构应用。 ***

9458061 Schadler Micromechanics problems critical to the failure of composite materials are examined. Laser Raman Spectroscopy (LRS), which can measure strain and phase changes with 2 micron spatial resolution, and x-ray stress analysis are the primarily tools used. Hydroxyapatite (HA), a ceramic material present in teeth and bones, is inherently brittle and, as a man-made material, is limited to nonstructural applications. Using LRS, the toughening of HA with zirconia is studied and the transformation zone mapped as a function of load, exposure to physiological solutions, and volume fraction of zirconia. Aqueous and organic environments are known to decrease the mechanical properties of graphite/epoxy composites. Degradation of the interface during exposure is a primary mechanism of composite failure. LRS is employed to monitor the integrity of the interface as a function of solvent polarity, temperature and time. In pursuit of computer-aided instruction techniques, appropriate hardware and software will be developed for use in polymer education. %%% This research should assist in the development of composite systems for structural applications. ***