Interval analysis of structures with uncertain-but-bounded axial stiffness

A method to evaluate the static response of structures with interval axial stiffnesses is proposed. The procedure overcomes the drawbacks arising in traditional interval analysis due to dependency phenomenon. The inversion of the interval stiffness matrix is pursued by means of a novel approximate relationship based on an interval-valued Sherman–Morrison–Woodbury formula. Numerical results on truss and frame structures evidence the accuracy and the effectiveness of the proposed approach to evaluate bounds of displacements and internal forces.