In this paper, a method for obtaining nonlinear sti ness coe cients in modal coordinates for geometrically nonlinear nite-element models is developed. The method requires application of a nite-element program with a geometrically nonlinear static capability. The MSC/NASTRAN code is employed for this purpose. The equations of motion of a MDOF system are formulated in modal coordinates. A set of ...

Modeling the soil–structure interaction (SSI) in seismic design involves use of soil response curves for single-degree-of-freedom (SDOF) structures; however, real structures have multiple degrees freedom (MDOF). In this study, shaking-table-derived p-y SDOF and MDOF superstructures were compared using numerical analysis. It was found that an structure experienced less displacement than same wei...

Abstract The aim of the contribution is creating of SDOF and simple MDOF models with included complex information of civil structures for dynamic analyses. The dynamic parameters of models are obtained as inverse problem solution. The inverse problem is defined as an optimization problem. The objective is to minimize the error index between measured response of the real structure and calculated...

Plastic energy dissipation is a key factor in the response of inelastic structures subjected to seismic input, and often regarded as primary source structural damage due deformation components. Accurately predicting structure’s plastic essential for efficient energy-based design assessment. While single-degree-of-freedom (SDOF) system provides simple effective method estimating dissipation, few...

Nonlinear structures exhibit complex behaviors that can be predicted and analyzed once a mathematical model of the structure is available. Obtaining such a model is a challenge. Several works in the literature suggest different methods for the identification of nonlinear structures. Some of the methods only address the question of whether the system is linear or not, other are more suitable for...

This paper presents a new identification technique combining the advantages of artificial neural network (ANN) and genetic algorithm (GA). In order to provide a neural network topology that can be merged into the GA identification technique developed by the author, the time history of the ground acceleration and the system parameters of a variety of SDOF systems are used as the input data of ne...