Discussion Forum

If you check the 1st attached image, it shows a multilayered portion of a circular "shell". In the middle layer (shaded in blue), I want to define a gradient in modulus such that the modulus decreases as one approaches the outside layer in a direction normal to the layer (I could call this the "radial" direction). I want to define a formula such that at each point in the blue layer, the modulus is computed in terms of the coordinates of the point as well as the values of the modulus values of the outer and inner layers, plus the thickness of the outer layer. I have done such a thing successfully in a simpler non-axisymmetric problem (see 2nd attached image of an example rod with a gradient in modulus defined in the middle; note equation for modulus in gradient region), but I am unsure how to translate this approach to the axisymmetric problem. I think my question boils down to this: When entering the formula for the modulus into "Materials", do I define it in terms of (r,z) coordinates or (x,y,z) coordinates? Thanks.