Tabulation of some layouts and virtual displacement fields in the theory of Michell optimum structures

In the theory of two-dimensional Michell optimum structures, there arises the problem of calculating the lines of principal stresses and the virtual displacements which are analogous to slip lines and velocities in plane plastic flow. A detailed analysis of the problem has been given in reference 1 and 2. Both analytical and numerical methods of calculation are given in reference 3.