Moment of Inertia Response
Create a Design Response that measures a component of the mass moment of inertia tensor in some region. For each tensor component, the response is computed by integrating one of the following functions: I_xx = rho * (y^2 + z^2), l_yy = rho * (x^2 + z^2), I_zz = rho * (x^2 + y^2), I_xy = l_yx = - rho * x * y, l_xz = I_zx = - rho * x * z, l_yz = I_zy = - rho * y * z over the region, where x, y, z are the coordinates of the material point in the given reference frame, and rho is the density field.