I'm looking either for online resources or reference to a good book. I've been trying to help someone with a homework problem in a course entitled, Elements of Mechanical Design which uses Mechanical Design of Machine Elements and Machines by Jack A. Collins. The book sucks. The system under analysis is a cantilevered bar with square cross section under torsion. The problem is to determine all stresses (shear and normal) at various points around the fixed end (all along the edges). The book explains that the maximum shear stresses will be at the midpoints of each edge, and that there will be zero shear stress at the corners. That's all fine and dandy, but when I go to calculate the other stresses I have no guidance. The book mentions how difficult it is to develop the equations, but it never presents them! Any ideas?