I often read on books that linear triangles do not have membrane locking for large deformations of plates/shells. I completely don't understand how this is possible. If one uses the well-known CST, stretching is measured as the increase in lenght of each edge of the triangle. Then, in the limit of the membrane stiffness going to infinity, clearly the solution cannot approximate any bending-dominated state, but rather it will be always rigid on general meshes (i.e. Minkowski theorem for convex bodies), allowing at most bending about few lines on very regular ones. What am I missing?

Hi,

I'm an Engineer and a Ph.D. student in Applied Maths, working in the field of Nonlinear Finite Elements for Elasticity. I often think about my future career since, by now, I have a strong experience with coding FE in C++/Matlab/Mathematica, but no clue whatsoever about commercial black-box softwares for FEA. I'm worried about this, since most of the job vacancies from the industry (I'm not interested in pursuing the Academic career) seem to require only experience with a specific software and application, and not to directly code FE.