Seismic soil-structure interaction analysis of wind turbines in frequency domain

Wind Energy ◽  
2016 ◽  
Vol 20 (1) ◽  
pp. 125-142 ◽  
Author(s):  
Amir Reza Ghaemmaghami ◽  
Oya Mercan ◽  
Reza Kianoush
Keyword(s):  
Frequency Domain ◽  
Wind Turbines ◽  
Soil Structure ◽  
Interaction Analysis ◽  
Soil Structure Interaction ◽  
Structure Interaction

DYNAMIC INFINITE ELEMENTS FOR SOIL-STRUCTURE INTERACTION ANALYSIS IN A LAYERED SOIL MEDIUM

2007 ◽  
Vol 07 (04) ◽  
pp. 693-713 ◽  
Author(s):  
C. B. YUN ◽  
S. H. CHANG ◽  
C. G. SEO ◽  
J. M. KIM
Keyword(s):  
Frequency Domain ◽  
Time Domain ◽  
Soil Structure ◽  
Interaction Analysis ◽  
Soil Structure Interaction ◽  
Shape Functions ◽  
Frequency Dependent ◽  
Structure Interaction ◽  
Infinite Elements ◽  
Stiffness Matrices

This paper presents the dynamic infinite element formulations that have been developed for soil-structure interaction analysis both in frequency domain and time domain by the present authors and our colleagues during the past 20 years. Axisymmetric, 2D and 3D layered half-space soil media were considered in the developments. The displacement shape functions of the infinite elements were established using approximate expressions of analytical solutions in frequency domain to represent the characteristics of multiple waves propagating into the unbounded outer domain of the media. The shape functions were determined in terms of the excitation frequency as well as the spatial and material characteristics of the far-field soil region. Thereby the element mass and stiffness matrices are frequency dependent. As for time domain analysis, the shape functions were further simplified to obtain closed-form frequency-dependent mass and stiffness matrices, which can analytically be transformed into time domain terms by the Fourier transform. The proposed infinite elements were verified using benchmark examples, which showed that the present formulations are very effective for the soil-structure interaction analysis either in frequency or in time domain. Example applications to actual soil-structure interaction problems are also given to demonstrate the capability and versatility of the present methodology.

Perfectly Matched Discrete Layers with Analytical Wavelengths for Soil–Structure Interaction Analysis

2018 ◽  
Vol 18 (09) ◽  
pp. 1850103 ◽  
Author(s):  
Dong Van Nguyen ◽  
Dookie Kim
Keyword(s):  
Frequency Domain ◽  
Soil Structure ◽  
Interaction Analysis ◽  
Soil Structure Interaction ◽  
Infinite Domain ◽  
Structure Interaction ◽  
Time Domains ◽  
Soil Media ◽  
System Properties ◽  
Discrete Layer

The importance of soil–structure interaction analysis has been proven by many researchers. It is obvious that soil media should be considered as an infinite domain to represent the radiation of waves into infinity. Perfectly matched discrete layer (PMDL) is one of the most promising methods to describe properly the infinite domain in soil media in frequency and time domains. In this research, a modified version of PMDLs that has a different strategy to determine their parameters is proposed. The method is named perfectly matched discrete layers with analytical wavelengths (AW-PMDLs). For verification of the proposed method, the dynamic compliances of strip foundations are analyzed and validated in the frequency domain. In the analyses, frequency-dependent system properties and hysteretic (material) damping are considered. The results show that the proposed procedure, AW-PMDL method, is effective for soil–structure interaction analysis in the frequency domain.

State-of-the-Art Techniques for Seismic Soil-Structure Interaction Analysis of Steel Gravity Structures

2014 ◽  
Author(s):  
Frederick Tajirian ◽  
Mansour Tabatabaie ◽  
Basilio Sumodobila ◽  
Stephen Paulson ◽  
Bill Davies
Keyword(s):  
Soil Structure ◽  
State Of The Art ◽  
Interaction Analysis ◽  
Layered Soil ◽  
Soil Structure Interaction ◽  
Soil System ◽  
Cyclonic Storm ◽  
Structure Interaction ◽  
Analysis Methods ◽  
Moderate Seismicity

The design of steel jacket fixed offshore structures in zones of moderate seismicity is typically governed by Metocean loads. In contrast the steel gravity structure (SGS) presented in this paper, is a heavy and stiff structure. The large mass results in foundation forces from seismic events that may exceed those created by extreme cyclonic storm events. When computing the earthquake response of such structures it is essential to account for soil-structure interaction (SSI) effects. Seismic SSI analysis of the SGS platform was performed using state-of-the-art SSI software, which analyzed a detailed three-dimensional model of the SGS supported on layered soil system. The results of this analysis were then compared with those using industry standard impedance methods whereby the layered soil is replaced by equivalent foundation springs (K) and damping (C). Differences in calculated results resulting from the different ways by which K and C are implemented in different software are presented. The base shear, overturning moment, critical member forces and maximum accelerations were compared for each of the analysis methods. SSI resulted in significant reduction in seismic demands. While it was possible to get reasonable alignment using the different standard industry analysis methods, this was only possible after calibrating the KC foundation model with software that rigorously implements SSI effects. Lessons learned and recommendations for the various methods of analysis are summarized in the paper.

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