This monograph contains the developments of methods and tools to deal with structural uncertainties in the analysis of vibrating structures. This study was carried out to gain insight into the behavior of randomly parametered dynamical systems and to evolve computational tools to assess the reliability of large scale engineering structures. The formulation for the derivation of the stochastic dynamic stiffness matrix for a general curved Timoshenko beam element is presented. Subsequently, the method is extended to study the mean and variance of the stationary response of built-up structures when excited by stationary stochastic forces.