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Full-Text Articles in Engineering

Characterization Of Dynamic Structures Using Parametric And Non-Parametric System Identification Methods, Ayad Al Rumaithi Jan 2014

Characterization Of Dynamic Structures Using Parametric And Non-Parametric System Identification Methods, Ayad Al Rumaithi

Electronic Theses and Dissertations

The effects of soil-foundation-structure (SFS) interaction and extreme loading on structural behaviors are important issues in structural dynamics. System identification is an important technique to characterize linear and nonlinear dynamic structures. The identification methods are usually classified into the parametric and non-parametric approaches based on how to model dynamic systems. The objective of this study is to characterize the dynamic behaviors of two realistic civil engineering structures in SFS configuration and subjected to impact loading by comparing different parametric and non-parametric identification results. First, SFS building models were studied to investigate the effects of the foundation types on the structural …


Equipment Fragility Due To Shock Response, Christopher Y. Tuan Jan 2014

Equipment Fragility Due To Shock Response, Christopher Y. Tuan

Department of Civil and Environmental Engineering: Faculty Publications

Because of its simplicity, the shock response spectrum has become widely used as a means of describing the shock responses and fragilities of structures and equipment. This paper focuses on the drawbacks of using the shock response spectrum for defining equipment shock tolerance. A cantilever beam with a tip mass was used to model a hypothetical piece of equipment subjected to strong ground motion such as that caused by an explosion. The exact solution from a detailed modal analysis shows that multiple modes of response were excited. Contributions from higher modes can be more predominant than that from the fundamental …


The Effect Of Sensor Mass, Sensor Location, And Delamination Location Of Different Composite Structures Under Dynamic Loading, Albert Darien Liu Jan 2013

The Effect Of Sensor Mass, Sensor Location, And Delamination Location Of Different Composite Structures Under Dynamic Loading, Albert Darien Liu

Master's Theses

This study investigated the effect of sensor mass, sensor location, and delamination location of different composite structures under dynamic loading. The study pertains to research of the use of accelerometers and dynamic response as a cost-effective and reliable method of structural health monitoring in composite structures. The composite structures in this research included carbon fiber plates, carbon fiber-foam sandwich panels, and carbon-fiber honeycomb sandwich panels. The composite structures were manufactured with the use of a Tetrahedron MTP-8 heat press. All work was conducted in the Cal Poly Aerospace Structures/Composites Laboratory. Initial delaminations were placed at several locations along the specimen, …


Laboratory Evaluation Of Dynamic Characterization Methods For Rapid Condition Assessment Of Bridges, Jason Kyle Herrman Aug 2011

Laboratory Evaluation Of Dynamic Characterization Methods For Rapid Condition Assessment Of Bridges, Jason Kyle Herrman

Graduate Theses and Dissertations

The objective of this thesis was to devise and refine Structural Health Monitoring methods and the associated quantitative characterization methods with the specific goal of enabling rapid and reliable safety evaluations of bridges following natural or manmade hazards. Presently, the safety and serviceability of these transportation infrastructure assets for use in emergency response and recovery operations are evaluated through on-site visual inspections of individual structures by teams of specially trained engineers or technicians; a process that is manpower-intensive, subjective, and slow. Specifically, the researcher was able to identify and evaluate strategies and procedures for using dynamic testing methods to rapidly …


Coaxial Cable Sensors And Sensing Instrument For Crack Detection In Bridge Structures -- Phase I: Field Qualification/Validation Planning, Genda Chen, Fujian Tang, Zhi Zhou Nov 2009

Coaxial Cable Sensors And Sensing Instrument For Crack Detection In Bridge Structures -- Phase I: Field Qualification/Validation Planning, Genda Chen, Fujian Tang, Zhi Zhou

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The objectives of this study are to pre-test analyze a decommissioned RC bridge that is selected in consultation with New York State Department of Transportation (NYSDOT), and design and plan the field tests of the bridge for the performance qualification and validation of distributed crack sensors and a fast Electrical Time Domain Reflectometry (ETDR) instrument to their full potential. The scope of work includes: (a) Selection of a decommissioned bridge, (b) Pre-test analysis of the select bridge structure to evaluate its progressive damage and determine the locations for sensor deployment, (c) Design and planning of field tests of the select …


Structural Assessment Of Highway "N" Power Substation Under Earthquake Loads, Genda Chen, Dongming Yan, Zuocai Wang, Seth Justin, J. David Rogers, Kazi Rezaul Karim Oct 2009

Structural Assessment Of Highway "N" Power Substation Under Earthquake Loads, Genda Chen, Dongming Yan, Zuocai Wang, Seth Justin, J. David Rogers, Kazi Rezaul Karim

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, the Highway N Substation was analyzed with a finite element model (FEM) for its vulnerability. The 'rigid' bus and electric switch components were characterized with full scale shake table tests. Each component of the substation was carefully modeled with due considerations of mass density, stiffness and geometries. Based on the FEM, modal analysis was conducted to identify the natural frequencies of the structure along with their corresponding mass participation factors. In response spectrum and time history analyses, the dynamic responses of main components, such as 'rigid' buses and switches, were evaluated. The magnitude and location of the …


Assessment Of The Bill Emerson Memorial Cable-Stayed Bridge Based On Seismic Instrumentation Data, Genda Chen, Dongming Yan, Wenjian Wang, Man Zheng, Louis Ge, Frank Liu Sep 2007

Assessment Of The Bill Emerson Memorial Cable-Stayed Bridge Based On Seismic Instrumentation Data, Genda Chen, Dongming Yan, Wenjian Wang, Man Zheng, Louis Ge, Frank Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, both ambient and earthquake data measured from the Bill Emerson Memorial Cable-stayed Bridge are reported and analyzed. Based on the seismic instrumentation data, the vibration characteristics of the bridge are investigated and used to validate a three-dimensional Finite Element (3-D FE) model of the bridge structure. The 3-D model is rigorous and comprehensive, representing realistic dynamic behaviors of the bridge. It takes into account the geometric nonlinear properties caused by cable sagging and soil-foundation-structure interaction in the Illinois approach of the bridge. The FE model is successfully verified and validated by using the natural frequencies and mode …