NSF Young Investigator

对复合材料失效的关键微观力学问题进行了研究。激光拉曼光谱（LRS）可以以2微米的空间分辨率测量应变和相位变化，x射线应力分析是主要的工具。羟基磷灰石（HA）是一种存在于牙齿和骨骼中的陶瓷材料，它本身就很脆，作为一种人造材料，它仅限于非结构应用。利用LRS对氧化锆对羟基磷灰石的增韧进行了研究，并绘制了转化区与负荷、暴露于生理溶液和氧化锆体积分数的关系图。已知水环境和有机环境会降低石墨/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。LRS用于监测溶剂极性、温度和时间对界面完整性的影响。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。这项研究将有助于开发用于结构应用的复合材料系统。＊＊＊

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. ***