Dear Jean-François, There is no specific tool yet for that. You can have access to the tangent with 'element_K' in the generic assembly language (the unit tangent is then 'Normalized(element_K)') If you define a scalar quantity "u" on your 1D structure, then "Grad_u" will be the gradient of the quantity in the sense that it is a tangent vector whose norm is the derivative of the qunatity along the curve. So that "Grad_u.Grad_Test_u" is still the stiffness term for a curvilinear second derivative. For a vector quantity "u", "Grad_u" is the componentwise gradient.
Best regard, Yves. ----- Original Message ----- From: "Jean-François Barthélémy" <[email protected]> To: [email protected] Sent: Friday, November 17, 2017 6:17:13 PM Subject: [Getfem-users] Curvilinear structures in Getfem Dear Getfem users, I wonder whether it is possible to model simple linear elastic curvilinear structures submitted to traction, bending, torsion etc... in 2D or 3D in Getfem. I haven't found a way to have access to the tangential or normal parts of vectors in the local basis of a beam and their derivatives with respect to the curvilinear abscissa needed to build the formulation. Does someone have an answer please? Thanks in advance Best regards Jean-François
