there are different types of modulus it depends on what types of stress is acting on the material if its direct stress then then there is modulus of elasticity,if tis shear stress then its modulus of rigidity and when its volumetric stress it is bulk modulus and so on
modulus of elasticity = 15 Msi; poisson ratio = 0.3 modulus of rigidity = E/ ((2(1 + poisson)) = 5.8 Msi
modulus of elasticity, E, relates tension stress, s, to strain,e (s = Ee) modulus of rigidity, G, relates shear stress, t, to angular strain, g (t = Gg) modulus of rigidity G is related to E as G = E/2(1+u) whree u = poisson ratio
The rigidity modulus, also known as the shear modulus, is a material property that measures its response to shear stress. It is independent of the dimensions of the wire, such as its radius. Therefore, if the radius of the wire is doubled, the rigidity modulus remains unchanged. The deformation behavior of the wire may change due to the increased cross-sectional area, but the rigidity modulus itself is a constant for that material.
G = E/2(1+u) where G = mod of rigidity and u =poisson ration and E = young modulus
http://www.engineeringtoolbox.com/modulus-rigidity-d_946.html
The modulus of rigidity of a wire is a measure of its resistance to shearing deformation. It is typically represented by the symbol G and is expressed in units of pascals (Pa). The specific value of the modulus of rigidity for a given wire will depend on its material composition and properties.
It is around 40 GPa.
shearing stress to shearing strain
about 70 to 80 GPa
change in shape due to stress applied
flywheel