... Elastoplastic stability of triangular layeredplates, Proceedings of the 7thnational congress on Mechanics, Hanoi, 12-2002, pp.373-379.4. Dao Van Dung, Elastoplastic stability of triangular ... subjected to the com-pressible forces with the simply supported boundary condition, Proceedings of theseventh national conference on deformable solid mechanics, Doson 27-28, August,2004, pp. 129-137 ... equation (2.4) permits us to determine a critical load p∗. Because of the force p isnon-linear function of s, then the relation (2.4) is too non-linear to s.We can solve this equation by...