STRUCTURAL DYNAMIC MODELING TECHNIQUES

COURSE DESCRIPTION

The field of modal analysis and structural dynamics has expanded rapidly in recent years due to the development of improved techniques for system modeling. These techniques have become an important part of the product development cycle for designing cost effective structures.

This intensive, five day program provides a thorough coverage of recently developed techniques. Basic modal analysis topics will be covered briefly so as to spend the maximum amount of time discussing more advanced system modeling/modification techniques.

This course is intended for engineers working in the field of modal analysis/structural dynamics. Some knowledge of finite elements, vibrations and modal analysis would be beneficial. Course material emphasizes developing and full utilizing the analytical/experimental data bases.

COURSE OUTLINE

Day 1

• Introduction and Overview
• Present seminar "theme" structure
• Review SDOF and MDOF systems
• Review linear algebra topics
• Analytical model generation
  • FEM techniques
  • model reduction techniques (Guyan, IRS, SEREP)
  • eigensolution techniques
• System response
  • modal participation factors
  • time/frequency domain response

Day 2

• System model development
  • modal space representation
  • combining system components
  • modal truncation effects
  • rigid body modes
• Structural Dynamic Modification
  • complex mode modifications
  • group modification procedures
  • local eigenvalue modification
  • mass, damping, stiffness changes
  • truss/general beam modifications

Day 3

• Analytical/Experimental Modal
  • time, frequency, Laplace forms
• Experimental Modal Overview
  • digital signal processing
  • excitation techniques
  • pretest considerations
  • modal parameter estimation
  • modal model verification
• Advanced Experimental Topics
  • multiple input/output concepts
  • advanced parameter estimation

Day 4

• Estimation of RDOF for test data
  • static, dynamic, SEREP methods
• Modal vector scaling methods
  • scaling of FEM and test modes
  • rigid body mode scaling
• Structural Dynamic Modification
  • use of test data for modification
• Modal vector correlation techniques
  • MAC and COMAC
  • Pseudo Orthogonality Check
  • Coordinate Orthogonality Check

Day 5

• Analytical Model Improvement
  • development of mass/stiffness
  • model optimization/improvement
• Localization of Model Changes
  • Forward optimization methods
  • Inverse optimization methods
  • Use of skyline constraints
  • Higher order element updating
• Non-linear Response Techniques
  • time and frequency methods
  • physical and modal models
  • analytical/experimental models
• Non-linear Response Techniques
  • time and frequency methods
  • physical and modal models
  • analytical/experimental models
  • ERMT, MMRT and CEM
• Force Approximation Techniques

Sessions will run from 8:30AM to 4:30PM daily with a lunch break from 12:00 to 1:00PM. Optional evening sessions will be held in the laboratory to demonstrate topics covered during class sessions or to discuss participant's particular questions or problems.

PRESENTERS

John C. O'Callahan, Ph.D., is a Professor of Mechanical Engineering and Director of the Computer Aided Engineering Design Center. A consultant and researcher with over 30 years experience in finite element methods as well as analytical and experimental modal analysis, Dr. O'Callahan has developed numerous software packages for finite element and modal analysis, with particular emphasis on combining these databases for use in dynamic analysis of structures.

Peter Avitabile, Ph.D., is the Manager of the Modal Analysis and Controls Laboratory supporting testing and research projects. His industrial experience includes analytical and experimental modal analysis, signal processing, and finite element modeling. He is mainly involved in testing, analysis and correlation studies in the laboratory.

Other well-known lecturers from industry and other universities have participated in presentation of some of the material for this seminar. All lecturers have published many papers in the field of modal analysis and structural dynamics, with numerous presentations at the International Modal Analysis Conference.

Some other typical seminars presented are:

 Society for Experimental Mechanics offers

• Modal Analysis: Theory and Practice is a 3 day course which covers a broad assortment of experimental modal analysis topics
• Model Correlation and Updating is a 3 day course which addresses correlation techniques leading into the adjustment of finite element models

 Spectral Dynamics offers

• Basic Modal Analysis seminar concentrating on introductory concepts for the development of an experimental modal model using FFT data with STAR
• Advanced Modal Analysis seminar extends the basic seminar to include advanced manipulation of experimental data

 LMS N.America offers

• Basic Modal Analysis seminar concentrating on introductory concepts for the development of an experimental modal model using LMS hardware/software
• Advanced Modal Analysis seminar extends the basic seminar to include advanced manipulation of experimental data using LMS software for advanced techniques for manipulation of measured and analytical data.
• Model Correlation and Updating is a 3 day course which addresses correlation techniques and updating of finite element models using the LMS software packages

 Speciality Seminars for Industry have been developed on request to address specific topics pertaining to testing, analysis, correlation, model updating, etc. as well as emerging techniques for solving perplexing problems

For more information about the seminar, contact: Peter Avitabile at (978)-934-3176 or e-mail at Peter_Avitabile@uml.edu

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