Effect of crystallographic anisotropy and irradiation on fatigue and fracture of metals

真实的材料是高度各向异性的微晶的复杂的、不均匀的集合。它们的平均响应可以接近在实际应用中经常假设的各向同性行为。 然而，如果不考虑固有的不均匀行为，就无法理解许多反应。织构发展、耳环、晶间破坏、应力腐蚀开裂和许多其他效应不取决于平均应力，而是取决于局部行为和平均应力周围的应力分布。当这种材料受到循环载荷时，它们会发生不可逆的微观结构变化。 经过多次疲劳循环后，裂纹开始并通过试样传播，直到发生失效-这是研究计划的主题。

Real materials are complex, inhomogeneous collections of highly anisotropic crystallites. Their mean response may approach the isotropic behaviour often assumed in practical applications.  However, many responses cannot be understood without accounting for the inherently inhomogeneous behaviour. Texture development, earring, intergranular failure, stress corrosion cracking and many other effects are dependent not on average stress, but rather on the local behaviour and the distribution of stresses around the average. When such materials are subjected to cyclic loading, they undergo irreversible microstructural change. After a number of fatigue cycles, cracks initiate and propagate through the specimen until failure occurs - this is the topic of the research program.