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

真正的材料是高度各向异性的复杂、不均匀的微晶集合。它们的平均响应可能接近实际应用中经常假定的各向同性行为。然而，如果不考虑固有的不均匀行为，许多响应是无法理解的。织构发展、耳环、晶间失效、应力腐蚀开裂和许多其他影响不是取决于平均应力，而是取决于局部行为和平均附近的应力分布。当这种材料受到循环载荷时，它们经历了不可逆的微观结构变化。经过几次疲劳循环后，裂纹开始并在试件中扩展，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.