Interval eigenvalue analysis for structures with interval parameters

In this paper, a new method to solve the uncertain eigenvalue problem of structures with interval parameters is presented. The expressions of the interval stiffness matrix and interval mass matrix are developed directly from the interval parameters. With matrix perturbation and interval extension theory, the algorithm for interval eigenvalue analysis is discussed. The computations are based on the element level thus simplifying the calculations greatly, while the sharp bounds are guaranteed by the interval operations. Two numerical examples, a box cantilever beam and an automobile frame both with interval parameters, are given to show the validity of the presented method. (C) 2002 Elsevier Science B.V. All rights reserved.