Young's modulus surface and Poisson's ratio curve for orthorhombic crystals

The general expressions for the compliance s(ijkl)', Young's modulus E(hkl) and Poisson's ratio upsilon(hkl,theta) along arbitrary loading direction are given for orthorhombic crystals. The representation surface for which the length of the radius vector in the normal direction of the (hkl) plane equals to E(hkl) and representation curve for which the length of the radius vector with angle theta deviated from the reference directions [00 (1) over bar], [00 (1) over bar], [100], [00 (1) over bar], [10 (1) over bar] and [01 (1) over bar] equals to upsilon(100, theta), upsilon(010, theta), upsilon(001, theta), upsilon(110, theta), upsilon(101, theta) and upsilon(011, theta) respectively, are constructed for 12 orthorhombic crystals Aragonite, Baryte, Celestite, Iodic acid, Magnesium sulfate, Rochelle salt, Sodium tartrate, Strontium formate, Sulfur, Topaz, alpha-Uranium and Zinc sulfate.