Anisotropic mechanical behaviour experimental studies

Experimental studies of anisotropic mechanical behaviour and their interpretation... 

EXPERIMENTAL STUDIES OF ANISOTROPIC MECHANICAL BEHAVIOUR 147 which leads to a birefringence A , given by... 

Experimental Studies of Anisotropic Mechanical Behaviour and Their Interpretation... 

Since some earlier work based on anisotropic elasticity theory had not been successful in describing the observed mechanical behaviour of NiAl (for an overview see [11]), several studies have addressed dislocation processes on the atomic length scale [6, 7, 8]. Their findings are encouraging for the use of atomistic methods, since they could explain several of the experimental observations. Nevertheless, most of the quantitative data they obtained are somewhat suspicious. For example, the Peierls stresses of the (100) and (111) dislocations are rather similar [6] and far too low to explain the measured yield stresses in hard oriented crystals. 

---