The displacement bound estimation for structures with an interval description of uncertain parameters

A structure subjected to interval parameters and interval loads which are unknown, except for the fact that they belong to given intervals, is studied and the displacement bound estimation is given. These parameters are uncertain, and yet they are not treated as being random since no information is available on their probabilistic characteristics. A set of possible states of the system is described by interval matrices. The perturbation method is employed as a simple analytical tool for determining static responses - interval displacements of finite element equilibrium equations with interval parameters. The numerical results show that the proposed method is extremely effective.