Vibration-Based Seismic Damage Identification in Buildings

2005 ◽  
Vol 293-294 ◽  
pp. 727-734
Author(s):  
José L. Zapico ◽  
María P. González
Keyword(s):  
Natural Frequencies ◽  
Damage Identification ◽  
Element Model ◽  
Seismic Damage ◽  
Frame Structure ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Data Errors ◽  
Simplified Finite Element Model ◽  
Storey Building

This article deals with a method for seismic damage identification in buildings with steel moment-frame structure. The damage identification is based on artificial neural networks and natural frequencies. A simplified finite element model is used to obtain the data needed for training the nets. The method is simulated on a four-storey building under conditions as close as possible to reality. The robustness of the method and its sensitivity to the variations of the mass with time and the influence of the data errors is addressed. The statistical analysis of the results is successful, but it reveals that the predictions are quite sensitive to the data errors.

Displacement-Based Seismic Design Method of Steel Moment Frame

2012 ◽  
Vol 166-169 ◽  
pp. 640-644
Author(s):  
Qian Zhang ◽  
Ya Feng Yue ◽  
Ergang Xiong
Keyword(s):  
Seismic Design ◽  
Design Method ◽  
Steel Frame ◽  
Frame Structure ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Displacement Based ◽  
Seismic Design Method ◽  
Steel Frame Structure ◽  
Displacement Based Seismic Design

According to lots of documents previously studied, a seismic design method is put forward based on displacement for steel moment frame. This method is established in condition that the yield displacement of steel frame can be determined by its geometrical dimension; then the objective displacement (ultimate displacement) can be determined in light of performance level of the structure, and the corresponding coefficient of ductility can be obtained. Thereafter, the design base shear of steel frame structure can be calculated by the use of reduced elastic spectrum. Thus, the design of stiffness and capacity can be conducted on steel frame structure. The analysis of case study indicates that the displacement-based seismic design method addressed herein is of reasonable safety and reliability, and of operational convenience, which can still realize the seismic design of steel frame structure at different performance levels.

Finite Element Model Updating Approach to Damage Identification in Beams Using Particle Swarm Optimization

2008 ◽  
Author(s):  
Mohamed M. Saada ◽  
Mustafa H. Arafa ◽  
Ashraf O. Nassef
Keyword(s):  
Finite Element ◽  
Particle Swarm Optimization ◽  
Finite Element Model ◽  
Natural Frequencies ◽  
Damage Identification ◽  
Model Updating ◽  
Particle Swarm ◽  
Element Model ◽  
Pso Algorithm ◽  
Swarm Optimization

The use of vibration-based techniques in damage identification has recently received considerable attention in many engineering disciplines. While various damage indicators have been proposed in the literature, those relying only on changes in the natural frequencies are quite appealing since these quantities can conveniently be acquired. Nevertheless, the use of natural frequencies in damage identification is faced with many obstacles, including insensitivity and non-uniqueness issues. The aim of this paper is to develop a viable damage identification scheme based only on changes in the natural frequencies and to attempt to overcome the challenges typically encountered. The proposed methodology relies on building a Finite Element Model (FEM) of the structure under investigation. A modified Particle Swarm Optimization (PSO) algorithm is proposed to facilitate updating the FEM in accordance with experimentally-determined natural frequencies in order to predict the damage location and extent. The method is tested on beam structures and was shown to be an effective tool for damage identification.

A Study on Vibration-Based Damage Detection and Location in an Aircraft Wing Scaled Model

2006 ◽  
Vol 3-4 ◽  
pp. 309-314 ◽  
Author(s):  
Irina Trendafilova
Keyword(s):  
Damage Detection ◽  
Natural Frequencies ◽  
Element Model ◽  
Vibration Response ◽  
Mode Shapes ◽  
Aircraft Wing ◽  
Scaled Model ◽  
Damage Location ◽  
Wing Model ◽  
Simplified Finite Element Model

This study investigates the possibilities for damage detection and location using the vibration response of an aircraft wing. A simplified finite element model of an aircraft wing is used to model its vibration response. The model is subjected to modal analysis- its natural frequencies are estimated and the mode shapes are determined. Two types of damage are considered - localised and distributed. The wing model is divided into a number of volumes. The goal of the study is to investigate the possibility to use the vibration response of an aircraft wing and especially its modal characteristics for the purposes of damage detection. So we’ll be trying to find suitable features, which can be used to detect damage and restrict it to one of the introduced volumes. The sensitivity of the modal frequencies of the model to damage in different locations is studied. Some general trends in the behaviour of these frequencies with change of the damage location are investigated. The utilization of the modal frequencies for detecting damage in a certain part of the wing is discussed

Viscous-Fluid-Spring Damper Retrofit of a Steel Moment Frame Structure

2008 ◽  
Author(s):  
Saif Hussain ◽  
Paul Van Benschoten ◽  
Mohamed Al Satari ◽  
Silian Lin ◽  
Adolfo Santini ◽  
...  
Keyword(s):  
Viscous Fluid ◽  
Frame Structure ◽  
Moment Frame ◽  
Steel Moment Frame

Response Surface Method for Updating Dynamic Finite Element Models

Volume 2 ◽  
2004 ◽  
Author(s):  
Kun-Nan Chen ◽  
Cheng-Tien Chang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Response Surface ◽  
Damage Identification ◽  
Model Updating ◽  
Response Prediction ◽  
Element Model ◽  
General Purpose ◽  
Frame Structure ◽  
Fe Model

A finite element model of a structure can be updated as certain criteria based on experimental data are satisfied. The updated FE model is considered a better model for future studies in dynamic response prediction, structural modification, and damage identification. A finite element model updating technique incorporating the concept of response surface approximation (RSA) requires no sensitivity calculations and is much easier to implement with a general-purpose finite element code. The proposed updating method was incorporated with MSC. Nastran to solve the updating problem for an H-shaped frame structure. The updated results show that the predicted and experimental modes are correlated well with high MAC values and with a maximum frequency difference of 1.5%. Moreover, the updated parameters provide a physical insight to the modeling of bolted and welded joints of the H-frame structure.

A Model of Steel Frame for Simulating Connection Fractures

2010 ◽  
Vol 452-453 ◽  
pp. 469-472
Author(s):  
Hong Bo Liu ◽  
Long Jun Xu ◽  
Shuang Li ◽  
Yong Song Shao
Keyword(s):  
Seismic Damage ◽  
Steel Frame ◽  
Frame Structures ◽  
Steel Beams ◽  
Northridge Earthquake ◽  
Seismic Evaluation ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Welded Steel ◽  
Panel Zone

Following the 1994 Northridge earthquake, widespread damages were discovered in welded steel moment frame buildings. In order to accurately simulate the typical seismic damage of welded steel moment frame structures, a new simplified model is proposed for performing seismic evaluation of welded steel moment frame structures. In this model, the slabs effect is considered, as well as the effects of the slip between slabs and steel beams, deformation of panel zone and connection fractures. Fracture toughness demands were evaluated in terms of the mode I stress intensity factor. The model was employed in simulation of seismic damage of Blue Cross Building which experienced fractured connections in the Northridge earthquake. It indicates that the model can accurately predict the earthquake response of welded steel moment frame structures and estimate the level of damage. The approach proposed in this paper has important meaning to the research on seismic damage of steel frame which may experience fractured connections.

Damage Detection of a Substructure Based on Response Reconstruction in Frequency Domain

2013 ◽  
Vol 569-570 ◽  
pp. 823-830 ◽  
Author(s):  
Jun Li ◽  
Siu Seong Law ◽  
Yong Ding
Keyword(s):  
Frequency Domain ◽  
Damage Identification ◽  
Structural Response ◽  
Element Model ◽  
Frame Structure ◽  
Identification Algorithm ◽  
Response Reconstruction ◽  
The Difference ◽  
And Performance ◽  
Response Vector

A substructural damage identification approach based on structural response reconstruction in frequency domain is presented. The response reconstruction is based on transforming the measured responses into responses at other locations with the transmissibility matrix and then the relationship between two sets of response vectors is formulated. The damage identification is conducted by minimizing the difference between a measured response vector and the reconstructed response vector. Measured acceleration responses from the damaged substructure and the finite element model of the intact substructure only are required in the identification algorithm. A dynamic response sensitivity-based method with the adaptive Tikhonov regularization technique is adopted for the damage identification with improved results from noisy measurements. A seven-storey frame structure is taken as an example to illustrate the effectiveness and performance of the proposed approach.

scholarly journals Reducing the lateral displacement of lead rubber bearing isolators under the near field earthquakes by crosswise dissipaters connected to rigid support structure

2021 ◽  
Vol 30 (4) ◽  
Author(s):  
Kourosh Talebi Jouneghani
Keyword(s):  
Base Isolation ◽  
Lateral Displacement ◽  
Near Field ◽  
Frame Structure ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Isolation System ◽  
Lead Rubber Bearing ◽  
Base Isolation System ◽  
The Stability

The purpose of base isolation is to absorb earthquake energy, prolong the life of the structure, and enable the structure to be similar to a rigid body. However, since resonance can occur due to the closeness of the period of structures to the long period and large velocity pulses of the near field earthquakes, the stability of these buildings greatly reduces, and with the large displacement above isolation level, sometimes, tendency of overturning is created in isolators leading to their destruction. The main objective of this study is to significantly reduce the lateral displacement of base isolation subjected to near field earthquakes. In this research, seismic response calculation has been carried out for five steel moment frame structure with the 3, 5, 8, 11, and 14 stories in two states of with and without stiff core structure and energy dissipaters. The analyses has been done under fourteen scaled records of seven near-source and seven far-source earthquakes. It has been shown that the lateral displacement of base isolation system can be reduced by 87% for low-rise buildings, and 77% for high-rise buildings.

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