Efficient stochastic finite element analysis of irregular wall structures with inelastic random field properties over manifold

摘要

In the stochastic finite element analysis of irregular wall structures considering material uncertainties, the random fields simulation and deterministic finite element analysis (FEA) are the two focuses. In this paper, we present an efficient stochastic finite element analysis procedure for irregular wall structures with inelastic random field properties. In the procedure, the geometry domains of irregular wall structures are deemed as two-dimensional (2D) manifolds. Then Isometric feature mapping (Isomap) is used to map the manifold to a 2D Euclidean domain, over which the well-developed stochastic harmonic function representation is applied to simulate the random field. Meanwhile, to accurately reflect the nonlinear behaviors of the irregular wall structures, we adopt an enhanced deterministic FEA method, which combines the multi-layered shell element, the softened damage-plasticity concrete model and the quasi-Newton solution with a two-level secant stiffness in a framework. Finally, the proposed approach is applied to the stochastic analysis of a U-shaped reinforced concrete shear wall to illustrate its feasibility and applicability. The results demonstrate that the proposed approach can effectively simulate the random fields over irregular geometry domains and can reproduce the representative stochastic inelastic behaviors of irregular wall structures. The approach can be further used in reliability or safety evaluation of structures.