Journal of Theoretical
and Applied Mechanics

40, 4, pp. 1001-1019, Warsaw 2002

A stochastic eigenproblem of beams with cracked cross-sections

Jan Drewko, Tran Duong Hien
A nonstatistical methodology is introduced for eigenproblems of cracked cross-sectional beam systems with random parameters. The formalism is based on a combination of the second-order perturbation technique and mean-centered second moment analysis. The system random parameters are defined by their first two probabilistic moments. Hierarchical equations are obtained and solved for the first two probabilistic moments for the eigenvalue field. As the system matrix is nonsymmetric, a procedure for the exact solution of the sensitivity equations is proposed with each eigenvalue derivative solved for separatively. Analytical and numerical aspects of the problem are discussed and illustrative results are given. The approach presented is general and may be employed for a wide class of problems of fracture mechanics.
Keywords: fracture mechanics; effective stiffness; stochastic eigenpair; second-order perturbation