Eventos Anais de eventos
CONEM 2018
X Congresso Nacional de Engenharia Mecânica
Towards a dynamic iterative coupling scheme applied to the transient response of rigid foundations interacting with soil profiles
Submission Author:
Otávio Tovo , SC
Co-Authors:
Otávio Tovo, Luis Filipe do Vale Lima, Daniela Damasceno, Josue Labaki, EUCLIDES MESQUITA
Presenter: Otávio Tovo
doi://10.26678/ABCM.CONEM2018.CON18-0113
Abstract
This article describes an iterative coupling scheme to analyze the transient dynamic response of structures interacting with distinct soil profiles. Structures with lumped parameters and linear equations of motions are solved by the Newmark integration scheme. The soil, on the other hand, is an unbounded domain presenting outgoing and nonreflected waves that withdraw energy from the excitation source. This effect is known as Sommerfeld radiation condition or radiation damping. The modeling of unbounded domains presenting radiation damping requires special techniques that incorporate this damping effect, such as the Boundary Element Method (BEM) or a semi-analytical method based on a Green’s function approach (GF). The stationary dynamic behavior of soils have been successfully solve by the BEM and GF strategies. Nevertheless, the transient dynamic response of structures interacting with unbounded domains is still limited to a few cases. In this article the stationary dynamic response of the soil has been obtained by GF methods for very high frequencies, which, in conjunction with the FFT algorithm, allows to obtain accurate soil impulse responses for small time steps. The soil response to arbitrary transient excitation is obtained by Duhamel’s convolution integral. Previous research results indicate that the iterative coupling scheme is highly dependent on the accuracy of the strategies applied to solve each subsystem. The convergence rate of the convoluiton integral with constant time interpolation is smaller than the one presented by the Newmark algorithm. This convergence rate discrepancy causes convergence failure in the iterative scheme. The present article describes a formulation and an implementation of a convolution integral with higher order time interpolation schemes, which is essential to improve the convergence properties of the proposed iterative scheme. This higher order convolution integrals are essential steps to formulate a robust iterative algorithm to determine the transient response of coupled soil-structure systems. The convergence rates of the proposed convolution integrals are compared with those of the classical Newmark algorithm.
Keywords
Dynamic Soil Structure Interaction, Transient foundation response, Iterative coupling procedure, Higher order Duhamel convolution integral
