Nanomechanics and Interphase Chemistry of Interfacial Fracture

南达科他州矿业学院和德克萨斯大学奥斯汀分校合作项目的主要目标是在精确的空间分辨率下确定复合聚合物-基质体系中相间化学和断裂力学之间的基本控制关系。这个程序将提供新的化学性质和力学行为的选择复合材料的界面区域之前，期间和之后的界面裂纹的通道的理解。将出现的新的实质性科学/基础工程包括：i)测量聚合物相间区域、内聚区/裂纹尖端区域以及断裂前后的纳米力学性能（应力-应变行为）。ii)对具有可控黏合剂和内聚性的系统进行密集而复杂的光谱、纳米和断裂分析。iii)由黏合带模型得出的间相性质与牵引分离规律的直接联系。利用互补的实验和分析工具，我们将把相间化学、形态和力学性能与从断裂实验和有限元分析中提取的牵引分离规律联系起来。为了实现这一目标，我们将应用一种新的混合模式断裂技术，红外（IR）和拉曼光谱，界面和原子力显微镜，单色x射线光电子能谱（XPS）和飞行时间二次离子质谱（ToFSIMS）。为了促进跨学科培训，学生每年将至少花一个月的时间在非家庭机构实验室，并定期使用视频会议讨论和辩论结果和计划。将鼓励代表性不足的少数民族参与这项研究事业。

9978678WinterThe primary goal of this collaborative project between the South Dakota School of Mines and the University of Texas at Austin is to determine, with exquisite spatial resolution, the fundamental governing relations between interphase chemistry and fracture mechanics in composite polymer-substrate systems. This program will provide new understanding of the chemical nature and mechanical behavior of the interphase regions of selected composite materials prior to, during and following the passage of an interfacial crack. The new and substantive science/basic engineering that will emerge includes: i) Measurement of nanomechanical properties (stress-strain behavior) of the polymeric interphase region, cohesive zone/crack tip region, and pre- and post-fracture. ii) Intense and sophisticated spectroscopic, nanoscopic and fracture analysis of systems with controlled adhesive and cohesive properties. iii) Direct linkage of interphase properties to traction-separation laws obtained from cohesive zone models.Using complementary experimental and analysis tools, we will relate interphase chemistry and morphology and mechanical properties to traction-separation laws extracted from fracture experiments and finite element analysis. To accomplish the objectives we will apply a novel mixed-mode fracture technique, infrared (IR) and Raman spectroscopies, interfacial and atomic force microscopies, and monochromatic X-ray photoelectron spectroscopy (XPS), and time of flight secondary ion mass spectrometry (ToFSIMS).To facilitate interdisciplinary training, students will spend at least one month each year in the non-home institution laboratory and will discuss and debate results and plans regularly using video conferencing. Under-represented minorities will be encouraged to participate in this research enterprise.