Nebojsa Sebastijanovic, P.E., Ph.D.
Professor, Mechanical Engineering Program Director
- Milwaukee WI UNITED STATES
- Allen Bradley Hall of Science: S201B
- Mechanical Engineering
Dr. Nebojsa Sebastijanovic's areas of interest include solid mechanics, machine design, and finite element analysis.
Education, Licensure and Certification
Ph.D.
Mechanical Engineering
University of California-Santa Barbara
2008
M.S.
Mechanical Engineering
University of California-Santa Barbara
2001
B.S.
Mechanical Engineering
McNeese State University
1998
Biography
Areas of Expertise
Accomplishments
Blue Key Honor Society
1998
Mu Omega Sigma Engineering Honor Society
1998
Outstanding Teaching Assistant Award
2003-2004, 2005-2006, 2006-2007
University of California-Santa Barbara
Affiliations
- Registered Professional Engineer (Mechanical Engineering)
- American Society of Mechanical Engineers (ASME) : Member
- American Institute of Aeronautics and Astronautics (AIAA) : Senior Member
- National Society of Professional Engineers (NSPE) : Member
- American Society for Engineering Education, ASEE : Member
- The International Society for Optical Engineering (SPIE) : Member
Social
Selected Publications
Capstone Design and Bachelor Thesis Experiences for an International Dual-Degree Mechanical Engineering Program
Proceedings of ICERI2016 Conference, Seville, SpainJ.E. Pakkala, D. Reger, N. Sebastijanovic
2016
The dual-degree program described in this work challenges students to identify and solve practical engineering problems. As is the case with most endeavours, it is necessary to work with team members and to conduct independent investigations. This program encourages the student to develop skills in both areas, providing a valuable introduction to future workplace challenges. One of the most valuable aspects of this program is that students are free to strike out on their own and work on projects of particular interest to them. They are nevertheless required to work on a team completing a group project, but can also follow their own path on a separate project. Each year several students choose to work on individual projects with topics that have included: vehicle dynamics; wind power; CFD and FEA analyses of wind-surf board components; regenerative braking; handheld camera stabilization, among others.
Adaptive structural control using global vibration sensing and model updating based on local infrared imaging
Structural Control and Health MonitoringLin, C.H., Sebastijanovic, N., Yang, H.T., He, Q., Han, X.
2011
This paper presents a hybrid structural health monitoring system that was connected to an adaptive structural control algorithm to improve the control performance. The proposed vibration-based global damage detection method is combined with a local damage identification method using sonic infrared imaging. The numerical model and the monitor are updated for continuous structural monitoring and control during future earthquakes. The previously developed damage diagnosis technique is enhanced by including an equivalent simplified lumped-mass model deduced from a complex frame structure. Changes in global dynamic response characteristics due to damaged members or joints are first observed and the damage can be detected and located during the earthquake event. After the earthquake event, local damage is inspected in detail using sonic infrared imaging. The example of a three-story steel frame structure with a damaged column and a damaged joint is presented to demonstrate and evaluate the usefulness and effectiveness of the proposed concept. Results from numerical simulations indicate that the adaptive control strategy based on model updating improves the control performance.
Detection of changes in global structural stiffness coefficients using acceleration feedback
Journal of Engineering MechanicsSebastijanovic, N., Yang, H.T., Ma, T.W.
2010
This technical note presents an extension of a previous study where two methods for detecting structural damage have been developed by using displacement and velocity measurements. In this study, acceleration feedback is used in detecting changes in global structural stiffness coefficients of lumped-mass-shear-beam models. The previously developed method relies on the decoupling of effects of changes in stiffness at different locations and the use of displacement or velocity feedback has proven to be effective. Extension to the use of acceleration feedback using existing formulation is not trivial in that the desired decoupling effect cannot be achieved by simple coordinate transformation because the acceleration itself is directly related to the stiffness coefficients. An approach to circumvent this difficulty is presented and it involves increasing the order of time derivatives of the linear system so that the acceleration becomes the “velocity” of the new system. The performance of the proposed method is demonstrated using an illustrative example of a three-story model with stiffness changes at different floors. Numerical studies are also conducted to evaluate the time horizons required to normalize monitor outputs for the effective and efficient detection of stiffness changes.
Panel Flutter Detection and Control Using Eigenvector Orientation and Piezoelectric Layers
AIAA JournalSebastijanovic, N., Ma, T., Yang, H.T.
2007
A basic eigenvector orientation approach has been used to evaluate the possibility of controlling the onset of panel flutter using a simple flat panel (wide beam) as an illustrative example. The use of the eigenvector orientation method for prediction of the flutter boundary (indicated by a gradual loss of orthogonality between two eigenvectors) was developed in a previous study and thus provide a lead time for possible flutter control.
Structural Damage Detection and Assessment Using Acceleration Feedback
Smart Structures and Materials 2006: Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace SystemsSebastijanovic, N., Ma, T., Yang, H.T.
2006
This paper presents a method for structural health monitoring using acceleration measurements. In a previous study a method for detecting, locating, and quantifying structural damages has been developed by directly using the time domain structural vibration measurements. However, only displacement and velocity measurements were used in that study. In this paper, acceleration measurements are used as feedback. Because it is more practical to measure acceleration using accelerometers, it is preferable to use acceleration rather than displacement and velocity measurements for the purpose of structural damage detection and assessment. However, using acceleration measurements is more difficult since the effects of different damages can not be decoupled completely as in the cases of displacement and velocity measurements. One approach of circumventing this difficulty is presented and it involves increasing the order of time derivatives of the linear system. The effectiveness of the proposed method using acceleration feedback is evaluated with illustrative examples of a three and an eight-story model. Results obtained are found to be comparable with results from simulations using displacement measurements as feedback.
An Eigenvector Orientation Approach for Detection and Control of Panel Flutter
Smart Structures and Materials 2005: Smart Structures and Integrated SystemsSebastijanovic, N., Ma, T., DiCarlo, A., Yang, H.T.
2005
A basic eigenvector orientation approach has been used to evaluate the possibility of controlling the onset of panel flutter using a flat panel (wide beam) as an illustrative example. The onset of flutter can be defined as the instance when two modes coalesce. Since eigenvectors for two consecutive modes are usually orthogonal, an indication of the onset of flutter condition can be observed earlier when they start to lose their orthogonality. Using eigenvector orientation method for the prediction of the flutter boundary (indicated by a gradual loss of orthogonality between two eigenvectors) was developed in a previous study and thus can provide a 'lead time' for possible flutter control. In this study, a basic simple beam element is used to model the panel (wide beam). As a first step, piezoelectric layers are assumed to be bonded on the top and bottom surface of the panel to provide counter-bending moments at joints between elements. The standard linear quadratic control theory is used for controller design and full state feedback is considered for simplicity. The controllers are designed to modify the system stiffness matrix in such a way to re-stabilize the system at the onset of flutter; as a result, flutter occurrence is offset to higher flutter speed. Controllers based on different control objectives are considered and the effects of control moment locations are studied as well. Potential applications of this basic method can be straightforwardly applied to plates and shells of laminated composites using finite element method.
