Finite element non-linear dynamic soil-fluid-structure interaction: Fid-Bau Portal

Finite element non-linear dynamic soil-fluid-structure interaction

Crouch R.S.

A strategy for simulating the dynamic response and permanent deformation of concrete structures sited on unbounded domains (and those bounded by fluids) is outlined here. In this review paper, the focus is on the constitutive model and development of a coupled continuum FE approach able to handle the dynamic far-field. A generalised elasto-plasticity constitutive model is described in some detail. The far-field dynamic radiation condition is satisfied analytically using the novel Scaled Boundary Finite Element (SBFE) method. Another issue touched upon is the identification of instability indicators; these potentially offering valuable engineering performance measures. Several different FE structural analyses are presented, including the response of a soil-embedded fluid-filled concrete tank and the soil-structure interaction of a pre-stressed concrete containment vessel (PCCV) hit by an aircraft. It is shown that the SBFE method can offer an accurate and efficient treatment for the dynamic far-field provided the number of time-steps is limited and the number of SBF elements is modest. Incorporation of the SBFE method into a fully coupled fluid-structure interaction analysis code using an element-by-element approach leads to considerable time-saving when tackling 3-dimensional problems.Several different instability indicators have been examined. This work is ongoing, but preliminary results suggest monitoring the diagonal terms in the element stiffness matrices may provide simple, rapid measures of the impending collapse.