Eventos Anais de eventos
MECSOL 2022
8th International Symposium on Solid Mechanics
TRANSIENT RESPONSE OF LINEAR BAR STRUCTURES INTERACTING WITH THREE-DIMENSIONAL SOIL PROFILES: COUPLING THE BEM WITH MODAL ANALYSIS
Submission Author:
EUCLIDES MESQUITA , SP , Brazil
Co-Authors:
Amauri Coelho Ferraz, Lucas Agatti Pacheco, EUCLIDES MESQUITA, Ronaldo Carrion
Presenter: Amauri Coelho Ferraz
doi://10.26678/ABCM.MECSOL2022.MSL22-0078
Abstract
This work reports an investigation on the in plane transient response of one-dimensional bar structures interacting with the dynamic response of three-dimensional soil profiles in the z direction. The analyzed system is comprised of a bar structure laying on a foundation block, which in turn is supported by a soil profile. In this coupled system the excitation may be external, that is, forces applied directly to the bar structure or on the foundation block, or internal, that is an excitation due to an incoming wave field that impinges upon the foundation block. From the methodological point of view, the transient response of the coupled soil-foundation-structure system is obtained by a modal superposition procedure in which the considered modal parameters, eigenfrequencies and eigenmodes, were synthesized by a procedure that already encompasses the influence of the soil response on the structural modal quantities. The classical structural modal analysis is performed in terms of relative displacements, that is the displacements of the structure relative to the block foundation displacements. The dynamic response of the structure in relative coordinates is coupled to the soil-foundation frequency response, which were synthesized by a 3D direct version of the Boundary Element Method. The coupling of the structural frequency response in modal coordinates with the soil frequency response allows the determination of frequency response functions (FRFs) for the coupled system, in which the soil response is already considered. Modified modal quantities are extracted from the FRFs of the coupled system rendering a set of orthogonal equations that can be integrated to obtain the system transient response. This approach also allows to include in the analysis an arbitrary number of structural modes. It is well known that the transient response of linear structures, depending on the kind of excitation mechanism, does not need to consider all the structural modes. With the approach described above, this article aims to make a modal analysis of a structure over a homogeneous half-space with a rigid layer under it. Besides that, it is intended to investigate the effects of the rigid layer on the structure modal quantities.
Keywords
Dynamic Soil Structure Interaction, Soil Dynamics, structural dynamics, Transient Response, Boundary Element Method, Modal Analisys
