Mechanical Sciences: Mixed Mode Fracture at Bimaterial Interfaces

本研究项目的目标是开发实验性的 用于直接评估断裂过程的工具 不同材料沿着其界面分离， 有助于理解层状固体的分层现象。在 特别是，局部断裂模式相互作用和粘弹性 将检查粘合剂或基质材料的性质， 对裂纹扩展速率的影响， 沿着不同材料之间的界面生长。 解释 的断裂过程将基于直接观察， 裂纹面位移的测量 在裂纹前缘区域的界面，使用光学 干涉测量法 将使用一种特殊构造的装载装置， 将垂直于和切向于界面的位移应用于相同的 裂纹侧面位移测量的准确度。 这种直接评估将用于确定 线性应力分析（静态裂纹）和局部断裂 控制界面起始和稳定扩展的准则 裂纹

The objective of this research project is to develop the experimental tools for a direct evaluation of the fracture processes that occur in the separation of dissimilar materials along their interface, with a view to understanding the delamination phenomenon of layered solids. In particular, local fracture mode interactions and the viscoelastic nature of the adhesive or matrix materials will be examined for their influence on the propagation rates of cracks that are constrained to grow along the interface between dissimilar materials. Interpretation of thefracture processes will be based on direct observation and measurement of the crack face displacements normal to and tangential to the interface in the region of the crack front, using optical interferometry. A specially constructed loading device will be used to apply displacements normal and tangential to the interface, to the same degree of accuracy as the measurements of crack flank displacements. Such direct evaluations will then be used to determine the validity of linearized stress analyses (for static cracks) and local fracture criteria that govern the initiation and steady propagation of interface cracks.