Đề tài tiến sĩ Structural Identification

Đề tài tiến sĩ Structural Identification

Structural Identification : Prestressed Concrete Girder Bridges for Strength Evaluation

Author: Anun Patjawit Year: 2005 Field of Study: Structural Engineering Abstract:

A research study for developing a procedure for monitoring structural condition of bridge structures, which eventually provides essential information used for bridge rating, has been conducted The study has been aimed for achieving a monitoring method that is relatively simple, convenient for use, economical and less

time-consuming, but can yield reliable results Impact testing and finite element techniques have been selected as the principal tools for acquiring dynamic characteristics of the structures to be studied.

After its successful application on idealized structures as structural steel and reinforced concrete beams in laboratory, impact testing has been conducted on the prestressed concrete bridge located in the provinces of central Thailand The critical dynamic responses of the bridge collected during the testing process were mode shape, natural frequency and flexibility matrix norm Next, finite-element analytical model was developed for the tested bridge and eigenvalue analysis was then performed Calibration of input data for the analytical model was also incorporated in the analysis so that the structural responses comparable to that obtained from the field test were resulted By performing truckload testing on the bridge, the developed finite element model was proved capable of yielding accurate structural responses under static loads as well The results from these finite element analyses were then used in bridge rating procedure The test bridges appeared to be in good condition according to their rating results In addition, the flexibility matrix norm, one of the critical structural parameters

introduced and studied along the way, was found to be the more effective indicator for monitoring the structural condition of bridge structures compared to mode shape and natural frequency This is due to its relatively high sensitivity to structural damage or deterioration Therefore, continual monitoring the values of flexibility matrix norm can provide for bridge engineers the guideline when rigorous bridge inspection shall be performed.

Chairman: Prof Worsak Committee: Dr Barry Prof Ogunlana

Component-based Information-oriented Framework for Integrated Structural Applications

Author: Naveed Anwar Year: 2004 Field of Study: Structural Engineering Abstract:

The mechanical and electronics industries have long embraced the idea of component-based manufacturing of their products Similarly, component-component-based software

development has gained wide acceptance within the computer science discipline and the software development industry Component-based software development is a logical extension of object-oriented concepts and the corresponding object technologies, which have pervaded in the software industry since the early 1990s No formal attempt has been made, however, to use component-based architecture for development of structural engineering applications, although several applications of object-oriented techniques have been explored and reported in literature.

The impact of Information Technology and the Internet on almost all disciplines and computer applications is significantly changing the traditional concepts of data processing and data orientation The overall structural design process can also be viewed as an information transformation process; hence the development of integrated applications using information orientation Information in the computing environment is being represented and communicated increasingly through markup languages, most notably Extensible Markup Language (XML) No significant efforts have been made in the structural engineering discipline to represent the design information in standard markup languages to make it universally accessible and understandable.

This research presents the overall framework for component-based software

development for integrated structural engineering applications using the principles of information transformation Once the components have been developed within this framework, specific applications can be developed by assembling them An

information-oriented review of the overall structural design process is carried out to develop the information content and transformations involved in this process This information transformation concept is then used to propose a framework for the development of software for integrated structural design applications including the identification of key packages, patterns, components, class hierarchies and object models Use of XML is proposed as the main information description and

communication standard The advantages of using the proposed framework are discussed along with application and implementation scenarios.

Chairman: Prof Worsak Kanok-Nukulchai Committee: Dr Dentcho N Batanov, Dr Pennung Warnitchai, Dr Kim Kidu External Committee: Prof Edward L Wilson