Model Distance–Based Global–Local Response-Sensitivity Indexes for Randomly Inhomogeneous Structures under Stochastic Excitations

Abstract

Linear engineering skeletal structures with spatially varying random stiffness and mass properties, acted upon by a set of random vibratory loads, are considered in this paper. The focus of the study is on characterizing the global–local response sensitivity indexes for this class of structures by taking into account dependency among system parameters and/or forcing functions. This is achieved by extending the recently developed tools for modeling the sensitivity indexes based on various definitions of probability distance measures to problems involving stochastic inhomogeneities. The study allows for the non-Gaussian nature of stochastic variations and employs Monte Carlo simulation strategies and stochastic finite-element modeling tools. The spatially varying random properties are discretized using the optimal linear expansion methods. Illustrative examples include studies on single-span beams under the combined action of a train of random moving masses and earthquake support motions, and randomly parameterized skeletal structures under biaxial earthquake support motions.